THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 
MRS.  PRUDENCE  W.  KOFOID 


COMPARATIVE 


Physiology  and  Psychology. 


A    DISCUSSION  OF  THE  EVOLUTION  AND   RELATIONS  OF   THE   MIND 
AND  BODY  OF  MAN  AND  ANIMALS. 


BY  S.  V.  CLEVENGER,  M.  D., 

SPECIAL  PATHOLOGIST  COUNTY    INSANE    ASYLUM,  CHICAGO?     MKMBKR  OK  THE   AMERICAN 

NEUROLOGICAL  ASSOCIATION,  AMERICAN  MICROSCOPICAL  SOCIETY,  AMERICAN  KLEC- 

TRICAL    SOCIETY,    AMERICAN    ASSOCIATION    FOR   THE    ADVANCEMKNT    OF 

SCIENCE,  CHICAGO  MEDICAL  SOCIETY  ;  EX-METEOROLOGIST  U.  S.  SIGNAL 

SERVICE;   COLLABORATOR  OF  THE  AMERICAN  JOURNAL  OF 

NEUROLOGY  AND  PSYCHIATRY,  AMERICAN  JOURNAL 

OF  NERVOUS  AND    MENTAL    DISEASE,  AND 

AMERICAN  NATURALIST; 

ETC.,  ETC. 


CHICAGO: 

JANSEN,  McCLURG,  &  COMPANY. 
1885. 


COPYRIGHTED 

BY  S.  V.  CI.EVENGEB, 

1884. 


Cowdrey ,  OUrk  &  Co.,  Printeri, 
Chicago. 


L  i  b 


PREFACE. 

Some  of  the  original  ideas  contained  in  this  book  have 
appeared  in  scientific  and  medical  publications,  such  as  the 
American  Naturalist  and  Journal  of  Neurology  and  Psychiatry, 
during  the  past  five  years,  as  the  author  presented  the  papers 
containing  them  to  biological,  microscopical,  medical  and  gen- 
eral scientific  societies.  In  their  condensed  form,  herein,  the 
separate  theses  are  revised  and  amended  in  conformity  with 
more  recent  psychological  and  anatomical  research. 

About  eleven  years  ago  the  plan  for  these  investigations  was 
formed  and  has  since  been  consistently  pursued  through  most 
discouraging  difficulties.  All  the  notes  accumulated  could 
not  be  compressed  into  a  volume  of  this  size,  and  the  author 
was  compelled  to  content  himself  with  including  enough  of 
the  mental  operations  of  man  to  fairly  illustrate  the  compara- 
tive method,  which  will  again  be  applied  especially  to  the 
mechanism  of  the  mind  of  man  in  a  forthcoming  work  to  be 
entitled  "  Psychology." 

Personally  made  studies  of  savages,  infants,  and  all  classes 
of  men  living  in  so-called  civilized  communities,  with  his  pub- 
lished and  unpublished  clinical  and  pathological  reports  of 
cases  of  insanity  enable  the  author  to  advantageously  review 
the  literature  of  psychology  and  psychiatry. 

His  intention  is  to  elaborate,  as  far  as  possible,  a  practical 
mental  science  which  will  reconcile  the  observations  of  anat- 


IV  PREFACE. 

omists,  psychologists  and  pathologists  with  direct  reference  to 
the  more  intelligent  treatment  of  insanity. 

The  author  has  been  greatly  assisted  in  his  labors  by  Dr.  E. 
C.  Spitzka,  Professor  of  Neuro-Anatomy  and  Pathology  at  the 
New  York  Post  Graduate  Medical  School,  and  Dr.  James  G. 
Kiernan,  Medical  Superintendent  of  the  County  Insane  Asylum, 
Chicago :  two  men  (in  the  exalted  sense  of  the  word),  whose 
efforts,  to  advance  the  science  of  psychiatry  and  render  more 
humane  the  treatment  of  the  insane,  have  been  a  prolonged 
but  successful  struggle  against  political  and  general  greed, 
ignorance  and  malevolence. 

Faraday,  Huxley  and  Tyndall  in  chemistry,  biology  and 
physics,  with  the  host  of  workers  in  nerve  phenomena  have 
afforded  the  materials  for  the  author's  work. 

Charles  Darwin  and  Herbert  Spencer  have  taught  him  how 
to  make  use  of  them. 


TABLE  OF  CONTENTS. 

CHAPTER   I. 

PAGE. 

INTRODUCTION,  .....  i 

CHAPTER    II. 
PRIMITIVE  LIFE  AND  MIND,  .  .  .  .6 

CHAPTER    III. 
ORGANOGENY,  .  ...  30 

CHAPTER   IV. 
GENESIS,  .  .  .  .  .  -47 

CHAPTER   V. 
DEVELOPMENT,    ......  59 

CHAPTER   VI. 
PHYSICS  OF  THE  CEREBRO-SPINAL  NERVOUS  SYSTEM,  107 

CHAPTER  VII. 
PHYSICS  OF  THE  SYMPATHETIC  NERVOUS  SYSTEM,        .       151 

CHAPTER   VIII. 
PHYSICS  OF  THE  NERVE  CELLS,       .  .  .  157 

CHAPTER    IX. 
PHYSICS  AND  CHEMISTRY  OF  THE  NERVOUS  SYSTEM,      .       162 


VI  TABLE   OE   CONTENTS. 

CHAPTER   X. 

PAGE. 

MENTAL  PHYSICS,      .  ...  170 

CHAPTER   XL 

MORPHOLOGY,  HISTOLOGY  AND  EVOLUTION  OF  THE  HU- 
MAN BRAIN,         .  .  .  .  .180 

CHAPTER    XII. 
PRIMARY  ACTIVITIES,  .  .  .  202 

CHAPTER   XIII. 

DERIVED  ACTIVITIES,  MAINLY  THE  EMOTIONS  AND  THEIR 

EXPRESSION,         .  .  .  .  .212 

CHAPTER    XIV. 
DERIVED  ACTIVITIES,  MAINLY  MENTAL,       .  .  234 

CHAPTER   XV. 
THE  LAW  OF  EXPEDIENCY  AND  OPTIMISTIC  CONCLUSION,      241 


Comparative  Physiology  and  Psychology. 


CHAPTER    I. 

INTRODUCTION. 

Insanity  will  be  better  understood  and  its  treatment  will 
become  more  scientific  in  proportion  to  the  development  of 
psychology,  based  upon  comparative  microscopic  anatomy  and 
a  physiology  into  which  molecular  physics  shall  enter  more  in 
the  future. 

Heretofore  the  mental  workings  have  been  discussed  chiefly 
by  a  class  called  metaphysicians,  many  of  whom  were  astute 
observers;  but  in  the  main  their  system  was  so  insufficient,  so  one- 
sided, and  their  deductions  often  so  absurd  as  to  discourage 
honest  investigators  and  cause  such  a  thing  as  a  science  of  the 
human  mind  to  be  looked  upon  as  chimerical,  and  even  though 
possible  to  achieve,  as  of  doubtful  use. 

The  study  of  the  mind  has  thus  fallen  into  disrepute  among 
many  scientists,  and  as  has  been  the  case  with  all  branches  of 
knowledge,  it  has  been  travestied  by  such  imposters  and  igno- 
ramuses as  phrenologists,  spiritualists,  mind-readers,  magneti- 
zers,  pseudo-psychologists,  and  has  been  honestly  assailed  by 
a  sprinkling  of  bewildered  metaphysicians,  with  rarely,  here 
and  there,  physiologists,  such  as  Carpenter,  Maudsley,  etc. 

It  is  not  intended  here  to  review  the  matter  historically.  In- 
cidentally it  will  appear  how  vast  has  been  the  influence  of 


2  CLEVENGER — Physiology  and  Psychology. 

Herbert  Spencer  and  Charles  Darwin  in  the  evolution  of  a 
sensible  psychology,  but  the  work  done  by  Huxley,  Wundt, 
Ribot,  Meynert,  Spitzka  and  a  few  other  special  workers  in  bio- 
logical fields  should  be  accorded  full  recognition. 

The  method  by  which  I  propose  to  examine  the  mind  is  an 
extension  of  Herbert  Spencer's  principles.  Analytical  and 
synthetical  applications  of  many  fields  of  research,  mainly  phys- 
iological. Comparative  embryology  and  physiological  chem- 
istry are  rapidly  clearing  the  way  for  safer  inductions,  though 
alone  they  would  be  insufficient  for  our  purpose.  Catholicity 
and  the  grasp  of  a  multitude  of  scientific  facts,  apparently  hav- 
ing but  little  to  do  with  the  subject,  will  give  succeeding  gen- 
erations safer  and  still  safer  bases  for  the  coming  comparative 
psychology,  which  will  rescue  both  mental  study  and  general 
medicine  from  empiricists  and  impostors. 

It  may  be  startling  to  many  of  my  readers  to  learn  that  the 
drift  of  physiological  inquiry  has  been  steadily  toward  the 
recognition  of  sensation  and  memory  and  all  the  vast  subsid- 
iary mental  processes,  correctly  and  incorrectly  called  emo- 
tions, feelings,  cognitions,  etc.,  as  modes  of  chemical  energy. 

Chemical  union  and  interchange  of  atoms  is  conceded  by 
all,  but  the  abjectly  ignorant,  in  other  life  phenomena,  as  in 
assimilation,  blood,  bone,  cartilage  and  muscle-building;  but 
the  nervous  system,  through  effects  of  olden  superstitious 
training,  has  been  regarded  as  in  some  way  exempt  from  the 
full  operation  of  natural  laws,  and  the  brain  is  looked  upon 
by  many  sincere  and  otherwise  well-informed  persons,  to-day, 
as  a  meeting  place  of  material  and  inscrutable  spiritual  laws. 

I  wish  to  be  understood  by  all  classes  of  thinkers,  for  a  fair 
beginning  will  acquit  me  of  ambiguity. 

That  mind  is  chemical  affinity,  or  allied  to  it  as  a  property 
of  matter,  seems  a  terribly  blasphemous  assertion  to  many  of 


CLEVENGER — Physiology  and  Psychology.  3 

the  old  superstitious  way  of  thinking.  To  such  who  cannot 
rid  themselves  of  their  fetiches  and  whose  bias  prevents  their 
intelligent  examination  of  any  physiological  study,  I  have 
nothing  to  say.  If  they  are  content  with  ignorance  they  must 
make  the  most  of  it ;  but  with  all  who  are  not  afraid  to  follow 
wherever  facts  will  lead  them,  whatever  their  inclination  to  be- 
lieve may  be,  we  may  meet  upon  the  common  ground  of 
acknowledging  that  there  is  an  UNKNOWN.  I  will  not  grant  an 
Unknowable,  for  to  set  limits  upon  what  may  be  disclosed  to  us 
in  the  future  argues  a  knowledge  of  where  science  will 
always  fail,  which  no  one  possesses.  That  is,  we  cannot  say 
that  we  will  never  know  certain  things,  for  each  century  moves 
the  preceding  limits  of  the  known  farther  into  what  has  been 
before  the  realm  of  the  unknown.  At  present  it  would  be 
arrogant  indeed  to  say  that  everything  was  known,  and  hence 
I  start  with  the  full  admission  of  ignoramus  as  to  ultimates, 
but  by  what  right  can  we  cry  ignorabimus  ?  Knowledge  be- 
ing relative,  who  shall  fix  the  boundaries  of  the  ultimate? 

Dualists  and  the  ecclesiastically  biased,  who  are  anxious  to 
throw  the  responsibility  of  the  universal  workings  upon  a 
capricious  influence  of  which  we  know  nothing,  should  be  con- 
tent with  this  acknowledgment  of  an  unknown  beyond.  With 
this  unknown  we  shall  have  nothing  whatever  to  do,  and  we 
will  proceed  at  once  to  consider  what  is  known  and  to  argue 
therefrom . 

If  the  monistic  philosopher,  who  recognizes  the  guidance  of 
one  universal  set  of  laws  in  nature,  be  told  that  he  is  assuming 
when  he  degrades  mind  to  the  level  of  chemical  affinity,  let 
him  reply  that  in  the  first  place  it  is  assumption  indeed  to  re- 
gard chemical  affinity  as  a  degraded  thing.  Rather  let  mind 
and  chemical  affinity  be  alike  considered  as  in  their  essence  un- 
known ;  let  them  be  honestly  regarded  as  alike  in  the  matter  of 


4  CLEVENGER — Physiology  and  Psychology. 

present  understandability,  and  admitting  that  we  do  assume  in 
claiming  this  relationship  of  mind  and  chemical  affinity,  we 
claim  that  the  assumption  will  be  fully  justified  by  the  deduc- 
tions. 

A  postulate  is  absolutely  necessary  to  an  argument,  and  you 
cannot  move  in  any  direction  without  one.  You  cannot  step 
out  of  your  house  without  having  premised  that  the  street 
exists,  nor  can  you  retrace  your  steps  without  the  supposition 
that  your  house  will  be  found  where  you  left  it. 

The  assumption  of  mind  having  evolved  from  chemical 
affinities  and  being  related  to  them  affords  us  somewhat,  and  a 
somewhere,  upon  which  to  advance;  and,  as  we  advance,  the 
consistencies  are  so  beautiful  and  the  inferences  so  unerring 
it  seems  inexpressibly  stupid  that  we  should  have  been  so  long 
in  the  dark. 

The  entire  fabric  will  be  a  triumph  of  monism,  for  if  we  set 
out  on  any  other  assumption,  such  as  the  dualistic  affords,  than 
that  mind  is  a  product  of  chemical  energy  and  other  natural 
forces  there  is  an  end  to  inquiry. 

The  baleful  influence  of  teleology  hangs  over  the  average 
physiologist  as  over  the  superstitious  laity,  and  debars  him 
from  seeing  things  as  they  really  are.  The  inability  to  con- 
ceive of  consciousness  as  a  product  of  the  motions  of  matter 
is  on  a  level  with  the  inscrutability  of  the  nature  of  ultimate 
force  and  atoms.  In  dealing  with  the  workings  of  the  mental 
mechanism  it  is  not  necessary  to  define  or  attempt  to  explain 
consciousness,  any  more  than  the  practical  electrician  or 
chemist  or  optician  finds  it  necessary  to  define  or  speculate 
upon  the  ultimate  nature  of  the  vibratory  terms  in  which  they 
deal.  As  the  physicist  increases  his  knowledge  of  how  matter 
and  motion  act  and  react  upon  each  other,  he  is  willing  the 
metaphysicians  should  quarrel  over  the  unknowable,  the  lunar 


CLEVENGER — Physiology  and  Psychology.  5 

politics.  With  the  dawn  of  comparative  psychology  the  truth 
began  to  appear,  theories  became  subordinated  to  facts  and 
not  facts  to  theories. 

Not  only  are  the  laws  which  bind  the  social  organism  simi- 
lar to  and  derived  from  those  which  govern  the  units  of  which 
it  is  composed,  but  the  protoplasmic  units  are  governed  by  the 
same  processes  down  to  chemical  affinities. 

H.  C.  Sorby*  estimated  the  number  of  molecules  in  I-IOOO 
inch  sphere  of  albuminous  substances  to  be : 

Albumen 10,000,000,000,000 

Water 5  2O,ooo,ooo,ooo,cxx) 

Water  in  molecular  combination 530,000,000,000,000 

and  claims  that  we  are  as  far  from  seeing  the  ultimate  consti- 
tution of  organic  matter  with  our  highest  and  best  powers  as 
the  naked  eye  is  from  seeing  the  smallest  objects  which  they 
now  reveal  to  us,  and  there  seems  no  hope  that  we  may  ever 
see  them,  for  light  is  too  coarse. 

This  is  a  limit  to  our  sense  appreciation  of  the  subject. 
Reason  enables  us  to  make  safe  guesses  beyond  the  senses, 
but  having  them  for  a  guide  and  acknowledging  that  science 
does  not  require  final  but  effective  causes.  • 


Presidential  address,  Royal  Micros.  Soc.,  Feb.  2,  1876. 


CLEVENGER — Physiology  and  Psychology. 


CHAPTER    II. 

PRIMITIVE    LIFE    AND    MIND. 

The  " selection"  of  food  which  is  suited  to  the  amoeba  be- 
comes "  selection  "  or  mere  chemical  attraction,  depending  upon 
how  you  look  at  it.  For  instance,  let  the  assimilable  pabulum 
consist  of  molecules  for  which  the  protoplasm  has  affinities  or 
attractions.  The  amoeba- will  not  only  be  drawn  to  it  locomo- 
torially,  but  will  fuse  about  it.  As  it  is  drawn  into  and  be- 
comes part  of  its  tissue,  there  is  undeniable  chemical  union. 
The  inert  resulting  matter  is  left  behind  or  excreted  in  the 
movements.  The  inert  matter  not  only  does  not  attract  the 
animal,  but  even  in  passing  to  or  over  it  the  assimilative  mo- 
tions are  not  provoked.  There  could  be  an  endless  wrangle 
over  the  nature  of  this  act  of  the  protozoon  for  it  involves  the 
most  weighty  considerations  in  all  life.  There  is  much  to  be 
said  on  all  sides,  but  the  moment  the  acknowledgment  is 
made  that  chemical  affinity  and  other  physical  influence  is 
not  the  so-called  will  power  of  the  amoeba,  that  moment  there 
is  an  end  to  investigation.  Admit  that  these  natural  causes 
exert  entire  control  of  the  protozoon,  and  forthwith  the  postu- 
late proves  its  correctness  in  exact  proportion  to  the  correct- 
ness of  the  logical  methods  used  in  reasoning  therefrom. 

Much  of  the  perplexity  into  which  the  student  has  been 
thrown  by  regarding  these  movements,  has  arisen  from  want  of 
consideration  of  the  composition  of  resultants  of  attraction  from 
many  points  in  the  medium  or  environment  due  to  light,  heat, 
eddies,  vortices,  disseminated  invisible  attracting  points,  the 
assimilative  process  itself  changing  the  conditions  of  attrac- 


CLEVENGER — Physiology  and  Psychology.  7 

tion.  In  plethora,  as  might  be  expected,  movements  cease, 
owing  to  combinations  being  satisfied  for  the  time.  Then,  too, 
the  simple  nature  of  protoplasm  has  been  by  no  means  proven. 
It  is  being  regarded  as  not  only  complex  through  atomic 
union,  but  as  holding  in  its  molecular  construction  secrets 
which  the  chemist  may  some  day  find  operative  in  the  inor- 
ganic affinities.  There  may  be,  as  has  been  surmised,  many 
kinds  of  protoplasm,  and  the  ultimate  basis-substance  may  be 
beyond.  The  ova  of  the  different  animals  seem  to  be  pro- 
toplasm plus  other  things,  differing  from  each  other  in  quantities 
and  composition.  We  know  that  certain  animals  add  to  their 
bodies  chemical  substances  which  form  tissues,  and  that  other 
animals  do  not,  showing  a  variability  of  selective  affinity.  The 
psychologist  who  attempts  to  explain  consciousness  on  the 
basis  of  molecular  reaction  is  no  more  at  a  loss  than  the  chem- 
ist who  accepts  such  words  as  catalysis  and  isomerism  as  rep- 
resenting acts  of  the  atoms. 

Starting  out,  then,  with  the  fair  understanding  that  the 
amoeba  moves  by  virtue  of  the  operation  of  physical  causes, 
and  that  speculations  upon  the  origin  of  matter  and  force  are 
foreign  to  the  subject,  we  will  see  to  what  the  assumption,  if 
you  choose  to  call  it  one,  will  lead. 

I  invite  earnest  attention  to  the  proposition  I  make  here  as 
corollary  from  the  apparent  volition  of  the  amceba  being  mol- 
ecular attraction.  Locomotion  and  prehension  of  the  amoeba  are 
due  mainly  to  extrinsic  forces  operating  immediately  upon  the  or- 
ganism. Whereas  these  phenomena  in  man  and  the  higher  inter- 
mediate rnetazoa  are  due  immediately  to  intrinsic  forces,  as  a  rule, 
preponderating  over  the  extrinsic,  but  nevertheless  the  extrinsic  re- 
main the  remote  causes  of  motion  in  all  animals.  In  this  there 
is  a  view  of  the  evolution  of  vojition  from  the  so-called  invol- 
untary, its  growth  from  the  chemical  affinities. 


8  CLEVENGER — Physiology  and  Psychology. 

The  belief  is  current  among  biologists  that  if  we  reverse  the 
• 
conditions  under  which  all  life  exists,  all  life  would  perish ;  if 

the  reversal  were  slowly  effected,  most  would  perish  and  but 
few  survive ;  if  inappreciably  slowly,  it  is  highly  probable  that 
the  number  of  surviving  forms  would  be  very  large.  The  sur- 
vival of  any  animal  is  evidence  of  its  consonance  with  its  sur- 
roundings, and  the  environment  not  only  modifies  and  acts 
upon  the  animal  to  develop  or  destroy  it,  but  also  from  our 
chemical  standpoint  originates  it.  Without  dipping  into  bio- 
genesis, spontaneous  generation  somewhere,  somehow,  is  con- 
sistent with  the  ground-work  of  our  essay,  but  we  will  avoid 
its  consideration. 

Spallanzani,  Duge,  Doyere  and  others  have  demonstrated 
that  infusoria  and  certain  low  worms,  the  rotatoria,  tardi- 
grada  and  some  Crustacea  are  capable  of  dessication  and  re- 
vival. The  suspension  of  the  major  evidence  of  life  function  by 
animals  under  changed  conditions,  whether  this  be  absolute 
dessication  or  not,  the  development  of  seeds  and  ova  after 
indefinite  quiescence,  point  toward,  if  they  do  not  fully  attest, 
the  merging  of  the  inorganic  into  the  organic  and  the  addition 
of  the  faculty  known  as  life  through  the  restoration  of  the 
medium,  water,  which  affords  the  means  for  the  molecular 
motions  which  go  to  make  up  all  there  is  in  life. 

So  the  restoration  of  frozen  fish,  and  as  Semper  cites,  "Am- 
phibia, Mollusca  and  other  forms  have  lived  years  without 
food."  He  "  kept  species  of  landsnails  for  years  wrapped  in 
paper  and  quite  dry  in  wooden  boxes  and  thus  wholly  without 
food,  and  many  of  them  are  at  this  day  alive  and  active."  His 
explanation  is:  "The  amount  of  nourishment  required  daily 
by  any  animal  must  naturally  be  equivalent  to  the  organic 
matter  which  is  daily  used  up  in  the  various  organs  to  keep 
up  the  vital  processes.  The  more  active  an  animal  is  the 


CLEVENGER — Physiology  and  Psychology.  9 

more  food  will  it  require.  But  the  vital  processes  of  animals 
as  low  in  the  scale  as  amphibia  or  univalves  are  extremely 
feeble;  their  respiration  even  under  the  agitating  influence  of 
propagation  fails  to  raise  temperature  appreciably.  In  such 
the  vital  process  may  be  reduced  to  a  minimum  without  loss 
of  life." 

The  whole  matter  is  one  of  degree,  for  warm-blooded  ani- 
mals live  but  a  little  while  unfed.  Hibernates  are  comparable 
in  condition  to  "cold-blooded,"  while  this  division  sustain 
arrest  of  nutrition  longer,  and  finally  in  the  lowest  forms  the 
approach  toward  almost  indefinite  suspension  leads  us  to  think 
that  there  is  a  point  where  life  and  mere  chemical  conditions 
are  identical :  the  repeated  withdrawal  of  that  which  renders 
life  evident  entailing  no  permanent  inconvenience.  Such 
embryos  as  are  capable  of  living  in  a  medium  such  as  strong 
alcohol  several  days,  point  to  the  mechanical  nature  of  certain 
low  stages  of  life  and  the  diminished  liability  to  destruction  of 
initial  forms  through  heterogeneity  of  environment.  The 
internal  tissues  of  man,  with  their  great  range  of  chemical 
natures  of  fluids  in  which  the  cells  thrive,  instance  this.  With 
differentiation  and  higher  organization  comes  the  increased 
necessity  for  stability  of  environment  paralleled  by  the  ability 
of  low  forms  to  reproduce  lost  members,  not  evident  in  devel- 
oped life. 

We  may  regard  the  amoeba  in  many  ways  as  having 
undergone  development  above  some  lower  forms,  but  pend- 
ing the  settlement  of  the  bathybius  question  and  with  a 
mere  glance  at  protista  and  pre-amcebic  life,  this  organism 
affords  us  a  convenient  starting  point  for  inquiry.  While 
physiologists  agree  in  its  possession  of  the  fundamental  activi- 
ties of  life  in  simplest  modes  of  manifestation,  they  usually 
content  themselves  with  a  mention  of  this  fact  and  proceed  to 


io        t       CLEVENGER — Physiology  and  Psychology. 

examine  complex  differentiated  tissues,  as  though  the  amoeba 
merited  no  further  attention.  From  my  way  of  looking  at  it, 
the  amoeba,  containing  the  solution  of  so  much,  deserves  very 
deep  consideration,  which  being  accorded  it  the  apparently 
simple  becomes  intricately  complex  in  that  it  explains  so 
much.  First,  the  environment  of  the  amoeba :  stagnant  water, 
mud  or  damp  earth,  or  from  the  infusion  of  any  animal  sub- 
stance in  water  and  allowing  it  to  evaporate  while  exposed  to 
direct  sunlight*  It  absorbs  oxygen  and  gives  out  CO2  at  45° 
C,  and  strong  shocks  of  electricity  kill  it.  Moderate  shocks 
of  electricity  cause  it  to  assume  the  globular  form.  Crushing 
kills  it,  and  then  even  the  nucleus  disappears.  Freezing  point 
arrests  its  motions.  In  its  surroundings  there  are,  besides  its 
food,  air,  water,  mineral  matter,  sunlight,  heat  and  cold,  and 
mechanical  vibrations. 

At  35°  it  heat  stiffens,  at  once  proving  the  development  of 
the  amoeba  for  its  medium  and  that  of  the  white  blood  cor- 
puscle, which  is  more  sluggish,  for  a  different  one,  the  tempera- 
ture of  the  blood  currents  of  the  different  animals.  This  may 
be  regarded  as  an  acquired  adjustment 

Its  molecules  are  subject  to  the  laws  of  gravitation;  light 
attracts  it;  heat  increases,  within  limits,  its  activity;  vibrations, 
such  as  eddies  of  its  medium,  move  it;  electricity  stuns  it;  its 
intimate  structure  assimilates  chemically  the  substances  for 
which  its  molecules  have  affinities,  and  being  nonresponsive  to 
those  for  which  it  has  not,  consigns  them  to  the  exterior. 

Now,  if  all  these  forces  act  upon  and  in  the  amoeba,  what  is 
to  prevent  external  forces  from  pulling  or  pushing  out  its 
pseudopodia  and  with  the  cohesion  of  its  mass  flowing  its 
granules  into  the  pseudopodium  most  attracted,  and  thus  its 
being  drawn  bodily  in  the  line  of  the  resultant  of  all  its 

*  Practical  Biology,  Huxley  &  Martin. 


CLEVENGER — Physiology  and  Psychology.  1 1 

external  and  internal  forces.     The    multiplicity  of  the  com- 
ponents  of  the   resultants  are  evident  upon  watching  it. 

However  highly  differentiated  the  desires  of  man  may  be, 
and  however  he  may  fail  to  recognize  the  attraction  of  his  own 
cells  for  pabulum,  as  soon  as  the  food  is  placed  within  reach 
of  the  enteric  cells  their  affinities  are  not  masked.  If  a  com- 
plex organic  protoplasm  has  the  capacity  of  chemical  conver- 
sion and  union  with  oxygen  and  other  molecules,  and  at  the 
same  time  the  union  of  oxygen  and  hydrogen  under  proper 
circumstances  is  through  such  conditions  favoring  the  mutual 
attraction  at  a  distance,  we  cannot  avoid  the  idea  that  a  similar 
effect  is  produced  upon  the  bioplasm,  and  that  affinity  for  its 
food  is  a  chemical  energy,  which  is  one  of  the  forces  forming 
with  other  modes  of  motion,  or  attraction,  a  resultant;  each  of 
these  attracting  inversely  as  the  square  of  its  distance  and 
directly  as  its  mass.  Because  the  protozoon  does  not  go 
straight  towards  its  food  it  is  thought  not  to  be  attracted  by 
it;  but  when  in  contact  the  pseudopodia  envelop  it,  then  it  is 
said  to  be  a  will  effort.  When  in  contact,  then  the  assimila- 
tion is  possible,  and  chemical  energy  asserts  itself  as  a  larger 
component  of  the  general  forces  which  make  resultant  motions  ; 
when  at  a  distance,  the  food  becomes  one  among  many  influ- 
ences upon  its  movements. 

Prehension,  which  is  here  evidently  locomotory,  is  for  the 
obtaining  of  food,  and  is  caused  by  a  number  of  natural  ex- 
trinsic forces  or  attractions  combined  with  a  lesser  number  of 
intrinsic  forces  or  attractions. 

Chemical  affinity  is  the  prime  cause  of  assimilation.  Loco- 
motion is  evidently  here  only  a  form  of  the  latter,  due  to  the 
former  as  a  direct  cause,  but  accidentally  aided;  often  inter- 
fered with,  by  other  similar  natural  forces,  inasmuch  as  the 
amoeba  may  be  drawn  away  from  its  food,  unless  it  be 


1 2  CLEVENGER — Physiology  and  Psychology. 

near  enough  or  there  be  a  compensatingly  large  enough 
amount  to  draw  it  against  opposing  attractions. 

Throughout  animal  life,  to  the  highest,  with  the  develop- 
ment of  food-procuring  faculties  this  rule  still  holds  good.  The 
more  the  faculties  increase,  the  more  direct  is  the  food  acquisi- 
tion, and  the  less  do  generally  cooperative,  but  in  this  regard 
interfering  processes  influence  food-procuring.  Atavism  is 
prominent  in  doing  that  which  drives  from  a  base  of  supplies 
or  want  of  foresight  in  improvidence. 

Prehension  is  an  accessory  to  locomotion  and  both  are  assim- 
ilative acts,  or  acts  which  have  for  their  end  the  assimilative. 

This  is  also  evident  in  full  development,  for  every  act  or 
movement  of  the  whole  body  is  of  a  prehensile  nature, — leg 
movements  take  hold  of  the  ground  through  gravitation  to 
carry  the  body  in  search  of  food ;  hands  and  arms  being  pre- 
hensile direct;  jaws  are  prehensile  in  their  food  grasp;  ribs  are 
prehensile  in  their  assisting  oxygen  introduction,  that  gas  being 
a  food.  In  snakes  the  ribs  are  locomotory  prehensile. 

We  thus  have  all  the  physical  forces,  including  gravitation 
and  chemical  energy,  acting  upon  the  low  organism  to  cause 
all  its  motions.  Just  as  the  heat  of  the  sun  overcomes 
the  earth's  gravity,  and  lifts  billions  of  tons  of  water  from  the 
ocean  to  allow  it  to  fall  again  in  obedience  to  terrestrial  attrac- 
tive force,  so  may  the  "vitality"  of  an  animal  or  plant  apparently 
working  against  physical  laws,  lift  the  child  from  the  embryo, 
the  tree  from  the  seed.  But  eventually  the  cycle  is  complete 
and  the  primitive  elements  are  separated  in  "death,"  to  re-enter 
at  once  upon  other  changes.  The  natural  forces  are  masked 
in  life  phenomena,  as  the  law  of  gravitation,  though  the  direct 
agent,  is  not  recognized  in  the  upward  rush  of  the  fountain. 

The  amoeba  assimilates  organic  matter  and  breathes  as  it 
uses  up  oxygen  and  exhales  carbonic  acid.  To  complete  the  ob- 


CLEVENGER — Physiology  and  Psychology.  1 3 

jective  study  of  the  amoeba  we  observe  that  it  grows  as  a  con- 
sequence of  its  eating,  and  that,  owing  to  its  growth  and  the 
operation  of  the  attraction  of  gravitation,  a  force  too  often 
neglected  in  consideration  by  physiologists,  fission  or  repro- 
duction occurs,  as  the  cohesive  attraction  of  its  molecules  can- 
not pass  beyond  a  certain  limit,  and  the  extra  weight  is  gravi- 
tated, excreted  off,  a  process  still  evident  in  all  animal  repro- 
duction and  through  excretory  channels  also.  We  see  that 
the  sexual  act  is  identical  in  this  so-called  neutral  form.  This 
is  more  apparent  in  other  protozoa  as  a  differentiation.  I  ap- 
pend my  article  on  this  subject  from  Science  (N.  Y.),  June  i, 
1881. 

"A  paper  on  Researches  into  the  Life  History  of  the  Monads, 
by  W.  H.  Dallinger,  F.  R.  M.  s.,  and  J.  Drysdale,  M.  D.,  was  read 
before  the  Royal  Microscopical  Society,  Dec.  3,  1873,  wherein 
fission  of  the  Monad  was  described  as  being  preceded  by  the 
absorption  of  one  form  by  another.  One  Monad  would  fix  on 
the  sarcode  of  another  and  the  substance  of  the  lesser  or  un- 
der one  would  pass  into  the  upper  one.  In  about  two  hours 
the  merest  trace  of  the  lower  one  was  left,  and  in  four  hours 
fission  and  multiplication  of  the  larger  Monad  began.  A  full 
description  of  this  interesting  phenomenon  may  be  found  in 
the  Monthly  Microscopical  Journal  (London),  for  October,  1877. 

"  Professor  Leidy  has  asserted  that  the  amoeba  is  a  cannibal, 
whereupon  Mr.  Michels,  in  the  American  Journal  of  'Microscopy, 
July,  1877,  calls  attention  to  Dallinger  and  Drysdale's  contri- 
bution, and  draws  therefrom  the  inference  that  each  cannibal- 
istic act  of  the  amceba  is  a  reproductive,  or  copulative  one,  if 
the  term  is  admissable.  The  editor  (Dr.  Henry  Lawson),  of 
the  English  journal  agrees  with  Michels. 

"Among  the  numerous  speculations  upon  the  origin  of  the 
sexual  appetite,  such  as  Maudsley's  altruistic  conclusion,  which 
always  seemed  to  me  to  be  far-fetched,  I  have  encountered 
none  that  referred  its  derivation  to  'hunger.  At  first  glance  such 
a  suggestion  seems  ludicrous  enough,  but  a  little  considera- 


14  CLEVENGER — Physiology  and  Psychology. 

tion  will  show  that  in  thus  fusing  two  desires  we  have  still  to 
get  at  the  meaning  and  derivation  of  the  primary  one — desire 
for  food.  The  cannibalistic  amoeba  may,  as  Dallinger's  Monad 
certainly  does,  impregnate  itself  by  eating  one  of  its  own  kind, 
and  we  have  innumerable  instances  among  algae  and  protozoa 
of  this  sexual  fusion  appearing  very  much  like  ingestion.  Crabs 
have  been  seen  to  confuse  the  two  desires  by  actually  eating 
portions  of  each  other  while  copulating,  and  in  a  recent  num- 
ber of  the  Scientific  American,  a  Texan  details  the  Mantis 
religiosa  female  eating  off  the  head  of  the  male  mantis  during 
conjugation.  Some  of  the  female  Arachnida  find  it  necessary 
to  finish  the  marital  repast  by  devouring  the  male,  who  tries  to 
scamper  away  from  his  fate.  The  bitings  and  even  the  em- 
brace of  the  higher  animals  appears  to  have  reference  to  this 
derivation.  It  is  a  physiological  fact  that  association  often 
transfers  an  instinct  in  an  apparently  outrageous  manner. 
With  quadrupeds  it  is  most  clearly  olfaction  that  is  most  related 
to  sexual  desire  and  its  reflexes,  but  not  so  in  man.  Ferrier 
diligently  searches  the  region  of  the  temporal  lobe  near  its 
connection  with  the  olfactory  nerve  for  the  seat  of  sexuality, 
but  with  the  diminished  importance  of  the  smelling  sense  in 
man  the  faculty  of  sight  has  grown  to  vicariate  olfaction :  cer- 
tainly the  *  lust  of  the  eyes  '  is  greater  than  that  of  other  special 
sense  organs  among  Bimana." 

"  In  all  animal  life  multiplication  proceeds  from  growth,  and 
until  a  certain  stage  of  growth,  puberty,  is  reached,  reproduc- 
tion does  not  occur.  The  complementary  nature  of  growth 
and  reproduction  is  observable  in  the  large  size  attained  by 
some  animals  after  castration.  Could  we  stop  the  division  of 
an  amoeba,  a  comparable  increase  in  size  would  be  effected. 
The  grotesqueness  of  these  views  is  due  to  their  novelty,  not 
to  their  being  unjustifiable. 

"  While  it  must  thus  seem  apparent  that  a  primeval  origin  for 
both  ingestive  and  sexual  desire  existed,  and  that  each  is  a 
true  hunger,  the  one  being  repressible  and  in  higher  animal 
life  being  subjected  to  more  control  than  the  other,  the  ques- 
tion then  presents  itself:  What  is  hunger?  It  requires  but 


CLEVENGER — Physiology  and  Psychology.  \  5 

little  reflection  to  convince  us  of  its  potency  in  determining 
the  destiny  of  nations  and  individuals  and  what  a  stimulus  it 
is  in  animated  creation.  It  seems  likely  that  it  has  its  origin  in 
the  atomic  affinities  of  inanimate  nature,  a  view  monistic 
enough  to  please  Haeckel  and  Tyndall." 

Dr.  Spitzka,  in  commenting  on  the  foregoing  in  the  same 
journal,  June  25,  1881,  says  : 

"  There  are  some  observations  made  by  alienists  which 
strongly  tend  to  confirm  Dr.  Clevenger's  theory.  It  is  well 
known  that  under  pathological  circumstances  relations,  oblit- 
erated in  higher  development  and  absent  in  health,  return  and 
simulate  conditions  found  in  lower,  and  even  in  primitive 
forms. 

"An  instance  of  this  is  the  pica  or  morbid  appetite  of  preg- 
nant women  and  hysterical  girls  for  chalk,  slate  pencils  and 
other  articles  of  an  earthy  nature.  To  some  extent  this  has 
been  claimed  to  constitute  a  sort  of  reversion  to  the  oviparous 
ancestry,  which,  like  the  birds  of  our  day,  sought  the  cal- 
careous material  required  for  the  shell  structure  in  their 
food.  ( ? )  There  are  forms  of  mental  perversion  properly 
classed  under  the  head  of  the  degenerative  mental  states  with 
which  a  close  relation  between  the  hunger  appetite  and  sexual 
appetite  become  manifest. 

"  Under  the  heading  '  Wollust,  Mordlust,  Anthropophagi* ' 
Krafft-Ebing  describes  a  form  of  sexual  perversion  where  the 
sufferer  fails  to  find  gratification  unless  he  or  she  can  bite,  eat, 
murder  or  mutilate  the  mate.  He  refers  to  the  old  Hindoo 
myth  Civa  and  Durga  as  showing  that  such  observations  in 
the  sexual  sphere  were  not  unknown  to  the  ancient  races.  He 
gives  an  instance  where,  after  the  act,  the  ravisher  butchered 
his  victim  and  would  have  eaten  a  piece  of  the  viscera ;  an- 
other where  the  criminal  drank  the  blood  and  ate  the  heart ; 
still  another,  where  certain  parts  of  the  body  were  cooked  and 
eaten."  * 

*  Ueber  gewisse  Anomalien  des  Geschlechtstriebes,  Von  Krafft-Ebing,  Archiv 
fr  Psychiatric,  VII. 


i6 


CLEVENGER — Physiology  and  Psychology. 


Nature  (London),  commenting  on  my  article,  quotes  :  "  Mul- 
ieres  in  coitu  nonnunquam  cervicem  marts  mordunt" 

The  locomotory,  which  exhibits  all  the  prehensile  acts 
undifferentiated,  is  a  product  of  a  number  of  natural  forces 
and,  so  far  as  we  can  speak  of  atoms  having  objects,  the  object 
of  locomotion  is  in  food  procuration. 

Prehension,  locomotion,  assimilation,  growth,  excretion,  re- 
production are  so  combined  as  to  appear  inseparable.  All  are 
molecular  motions,  integrating  to  form  mass  motions,  and  the 
latter  to  facilitate  the  first.  Keeping  this  in  sight  as  a  biologi- 
cal fact,  it  will  simplify  subsequent  inquiry. 

Adjustment  and  readjustment  of  the  animal  perpetually  oc- 
curs. The  reaction  of  the  protozoon  upon  its  environment  is 
possible  only  through  the  intimate  structure  of  the  animal 
having  been  modified  by  the  environment.  This  consists  in 
molecular  changes,  ending  in  mass  changes. 

This  tendency  is  exhibited  in  the  frequent  appearance  of  a 
part  unable  to  throw  out  pseudopodia,  which  gravitates  to  the 
rear,  and  thus  becomes  the  hinder  part.  This  occurs  in  the 
proteus  animalculae  temporarily  .and  in  other  amoeba  forms 
as  a  permanent  differentiation.  The  ectosarc  (Fig.  I ),  or 


FIG.  i.     An  Amoeba. 
a      Nucleus. 
b.     Vacuoles. 


•-mjmgjjji^., 
*-^i^MiiiSiii 


(From  Frey's  Histol°gy- 


outer  envelope,  is  composed  of  denser  but  mobile  materials, 
due  to  separation  of  granular  and  molecular  matter  by  natural 
causes. 

The  vacuoles,  or  little  transparent  points,  are,  with  reason, 
assumed  to  be  watery  or  gaseous  spots,  filtered  from  the  assim- 


CLEVENGER — Physiology  and  Psychology.  1 7 

ilative  process.  Their  constant  appearance  and  disappear- 
ance are  doubtless  chemical  and  mechanical.  The  CO2  and 
water  holding  in  solution  or  suspension  fine  excretory  mate- 
rial will  find  its  way  out  through  diffusion  and  the  elasticity  of 
the  sarcode,  with  other  large  particles  gravitating  out  through 
any  temporary  channel.  This  process  is  apparent,  though  bet- 
ter provided  for,  in  cloacal  animals,  whose  watery,  gaseous 
and  solid  excreta  are  poured  forth  from  fixed,  often  the  same, 
orifices.  The  gastraea  stage  is  the  condition  in  full.  If,  with 
ingestion  of  food  and  oxygen,  the  animal  increase  its  bulk 
faster  than  the  ectosarc  can  accommodate  itself  to  the  change, 
extraneous  matter,  such  as  carbonic  acid  and  water,  must  be 
propelled  away  from  the  protoplasm,  for  which  it  has  no  affin- 
ity; and  under  the  operation  of  incessantly  recurring  similar 
causes  it  is  not  surprising  that  this  rythmical  diastole  and 
systole  should  often  become  quite  regular. 

We  thus  have  inspiration  of  oxygen  as  an  assimilative  act 
in  its  affinity  for  the  protoplasmic  molecules,  together  with  the 
other  accretive  atomic  motions  and  elasticity  of  the  ectosarc, 
instituting  rythmic  contractions  to  expel  inert  products.  If 
this  be  admitted,  then  the  inspiratory  oxygenation  of  every 
enteric  and  arterial  cell  from  the  food  and  blood  is  the  direct 
cause  of  vermicular  motion  and  pulsation. 

The  motions  of  the  amceba  are  assimilatory,  prehensile, 
locomotory,  accretory,  inspiratory,  expiratory,  excretory,  re- 
productory. 

Turning  now  from  the  objective  method,  let  us  examine  this 
primitive  form  subjectively.  The  objections  to  an  application 
of  the  latter  process  to  amcebic  movements  are  equally  valid 
against  all  other  animals,  even  man.  We  know  nothing  of  the 
workings  of  consciousness  in  others  except  by  comparing  like 
effects  and  inferring  from  them  similar  causes.  We  have  the 

2 


1 8  CLEVENGER — Pliysiology  and  Psychology. 

various   molecular   and   molar  workings   of  the   amoeba  as  a 
guide  in  determining  what  it  feels,  likes  and  dislikes. 

Descartes  conclusion,  "  Cogito  ergo  sum,"  Huxley  regards 
as  non  sequitur.  I  would  merely  postulate  both  ends  of  the 
sentence  as  being,  for  physiological  study,  unassailable :  Sum 
et  cogito,  and  let  the  metaphysicians  wrangle  over  the  rest. 
The  amoeba's  functions  are  simple  but  nevertheless  the  same  as 
our  own.  Forthwith  we  must  assign  it  a  desire  for  food,  which 
desire  is  the  chemical  affinity  of  atoms ;  then  the  amoeba  hungers 

Prof.  E.  D.  Cope*  assigns  it  as  "  the  primitive  desire  and  a 
form  of  pain.  This  was  followed  by  gratification,  a  pleasure, 
the  memory  of  which  constituted  a  motive  for  a  more  evidently 
designed  act,  viz. :  pursuit." 

Dividing  these  primitive  desires  arising  from  (or  with,  if  you 
wish,)  the  atomic  affinities  into  those  which  subserve  and 
those  which  oppose  assimilative  processes,  we  have  the  origin 
of  pain  and  pleasure,  under  which  two  heads  all  conscious 
workings  may  be  classed.  Pain  increases  with  the  quantity 
of  atoms  unsatisfied.  As  long  as  there  are  protoplasmic  mole- 
cules with  affinities,  the  number  of  them  wanting  food  increases 
the  desire.  (Attraction  directly  as  the  mass).  Of  course,  as 
soon  as  destructive  starvation  breaks  down  the  molecule  the 
desire  ceases.  This  is  evident  in  the  final  loss  of  desire  for 
food  in  extreme  deprivation  in  man. 

All  unsatisfied  desire  is  painful,  as : 

Hunger  in  the  absence  of  food ; 

Desire  to  move  about  while  disabled  from  so  doing  ; 

Desire  to  excrete  when  prevented  by  any  cause ; 

In  the  act  of  satisfying  desires  pleasure  is  apparent; 

Hunger  is  appeased ; 

Movement  is  unconstrained; 

Emunctories  are  unobstructed  and  excretion  is  active. 
*  "  Origin  of  the  Will."     Penn  Monthly  for  June,  1877,  p.  446. 


CLEVENGER — Physiology  and  Psychology.  19 

All  pains  and  pleasures  are  relative  and  intense  in  propor- 
tion to  the  precedence  of  one  or  the  other  extreme. 

The  pangs  of  parturition  are  obstructive  excretory,  and 
what  obstetrician  has  not  noticed  the  happiness  of  accomplish- 
ment by  the  mother  ? 

A  pleasure  is  often  due  to  the  pre-existence  of  pain,  and 
bearing  upon  the  evolution  of  the  reproductive  excretory  cellu- 
lar into  a  desire,  which,  in  its  influence  upon  animal  life,  is 
second  only  to  that  of  hunger  ;  this  relativity  must  be  borne  in 
mind.  The  pleasurable  anticipation  of  eating  is  a  memory, 
the  physical  basis  of  which  in  the  amoeba  is  a  motion  of  the 
molecules  involved  in  assimilation  ;  their  activity,  their  tension 
(the  hungry  amoeba  is  always  more  active  than  when  fed).  The 
reproductive  excretory  is  in  the  amoeba  scarcely  to  be  called  a 
desire,  so  dependent  is  it  upon  the  performance  of  the  assimila- 
tive act.  The  desire  is  invoked  in  exact  proportion  to  growth 
from  assimilation,  provided  other  means  of  consumption  of  this 
growth  are  not  operative. 

This  is  obvious  throughout  all  animal  life.  When  hunger 
is  extreme  the  sexual  desire  is  absent. 

Full  meals  sometimes  excite  voluptuous  feeling.  The  re- 
pression of  this  excretory  desire  for  a  time  becomes  painful,  un- 
til readjustment  enables  vicariation. 

The  desire  to  excrete  the  sperm  cell  is  the  male  peculiarity, 
the  desire,  when  present,  of  the  female  being,  as  shown  in  the 
Science  article,  identical  with  hunger.  It  is  the  hunger  of  the 
ova,  which  are  part  of  the  female,  and  which  by  differentiation 
have  come  to  be  capable  of  satisfaction  in  the  manners  to  which 
they  have  grown. 

From  the  Synamceba  stage  in  its  denser  envelope,  prevent- 
ing the  escape  of  the  cells  for  a  longer  period,  this  sexual  ex- 
cretory desire  would  increase.  Differentiation  of  the  sexual 


2O  CLEVENGER — Physiology  and  Psychology. 

hunger  irom  the  general  hunger  is  shown  in  the  Drysdale  and 
Dallinger  Monad.      C.  M.  Hollingworth,*  on  the  "  Theory  of 
Sex  and  Sexual    Genesis,"   assigns    causes   determining   sex. 
"  Since  germ  cells  are  large  and  sperm  cells  are  small,  it  may  be 
at  once  inferred  that  where  they  are  found  in  different  parts   of 
the  organism  the  parts  in  which  germ  cells  or  their  producing 
organs   are   formed  must  be  parts  in  which  the  conditions  are 
especially  favorable  to  nutrition ;  and  that  the  parts  in  which 
sperm  cells  or  their  producing  organs  are  found,  must  be  rela- 
tively unfavorable  to  nutrition  and  favorable  to  cell  division." 


FIG.  2.  Amoeba  sphcerococus,  greatly  magnified.  A  fresh  water  amoeba  with- 
out a  contractile  vacuole.  A.  The  enclosed  amoeba  in  the  state  of  a  globular 
lump  of  plasma  (c]  enclosing  a  kernel  and  a  kernel  speck,  (a)  nucleus  and 
nucleolus.  The  simple  cell  is  surrounded  by  a  cyst  or  cell  membrane  (</). 
B.  The  free  amoeba,  which  has  burst  and  left  the  cyst  or  cell  membrane.  C.  It 
begins  to  divide  by  its  kernel  parting  into  two  kernels,  and  the  cell  substance 
between  the  two  contracting.  D.  The  division  is  completed,  and  the  cell  sub- 
stance has  entirely  separated  into  two  bodies  (D  a  and  D  b.} —  From  HAECKEL. 

"  The  hypothesis  is  that  a  relative  preponderance  of  the  con- 
ditions on  which  cell  division  depends,  causes  the  formation  of 
the  female  or  male  generative  organs  or  determines  the  sex  of 
the  individual."  Extending  this  to  the  amoeba,  the  pure  rela- 
tivity of  sex  is  seen.  If  the  amoeba  had  undergone  differen- 
tiation above  some  form  by  which  it  was  engulfed,  it  could  be 
regarded  as  the  male.  If  it  swallowed  a  synamceba  then  it  is 
the  female  cell,  and  the  product  of  this  sexual  eating  would  be 
either  male  or  female,  synamceba  or  amoeba,  according  to  the 

*  American  Naturalist,  July  and  August,  1884. 


CLEVENGER — Physiology  and  Psychology.  2 1 

preponderance  of  differentiating  influence  or  the  disposition  to 
increase  by  fission  in  the  resulting  fused  mass. 

Desires  consisting  of  atomic  tensions  or  affinities,  the  condi- 
tions of  continuance  or  satisfaction  of  desire,  involves  feeling 
or  sensation,  a  low  form  of  consciousness.  This  is  justified  in 
considering  our  developed  similar  states  during  the  same  pro- 
cess of  hungering,  eating,  etc.,  and,  as  in  us,  repletion  discon- 
tinues desire ;  so  does  it  in  the  lowest  form  of  life  we  are  dis- 
cussing. 

The  sensations  involved  in  assimilation  would  be  difficult  to 
separate  from  those  concerned  in  pseudopodia  protrusion  or 
general  locomotion,  as  they  are  identical  in  effect  in  the  amoeba. 
Admitting  this  identity,  it  is  easy  to  see  how  by  invagination  of 
the  ectoderm  the  later  differentiation  could  occur  by  an  enteric 
tactile  developing  in  one  direction,  while  the  ectodermal  would 
change  with  direct  reference  to  locomotion  or  prehension. 
But,  as  even  when  the  enteron  is  formed,  a  prehensile  tactile 
sense  is  retained  and  developed,  analogies  between  the  nerve 
distributions  to  external  and  internal  parts  remain,  though  the 
sensations  in  many  respects  differ.  The  passage  of  materials 
in  the  intestines  awaken  few  feelings  so  long  as  the  adjust- 
ment is  not  disturbed,  on  the  same  principle  that  we  do  not  feel 
external  ordinary  stimuli  perpetually  recurring. 

Pressure  is  the  feeling  of  constraint,  interference  with  molec- 
ular and  mass  movement;  it  is  a  painful  state  of  consciousness 
arising  from  the  inhibited  movement,  the  desire  to  move 
being  consequent  upon  proper  assimilation,  and  is  referred  to 
an  interference  with  that  function. 

The  hunger  pain  and  appeasing  hunger  pleasure  are  due  to 
and  consist  in  chemical  tensions  and  release  from  tension,  the 
absence  and  presence  of  certain  molecules. 

This   carried   up  the  scale   of  metazoa  convinces   us   that 


22  CLEVENGER — Physiology  and  Psychology. 

desire,  feeling,  sensation,  reside  in  every  living  cell  in  the  body, 
and  are  not  seated  exclusively  in  nerve  tissue.  With  the  dif- 
ferentiation of  function  there  will  proceed  changes  of  degrees 
of  intensity  of  certain  feelings  in  those  living  cells,  but  the 
fundamental  hunger  pain,  and  pleasure  of  its  gratification,  are 
never  differentiated  out  of  existence  in  any  cell. 

Desires,  feelings,  sensations,  consciousness,  cognitions,  ideas, 
memories,  emotions,  etc.,  are,  one  and  all,  conditions  of  the 
molecules  of  the  cells ;  and  in  the  ravenous  though  unavailing 
appetite  of  some  diseases  wherein  nutrition  is  at  fault,  the  feel- 
ing is  shown  not  to  be  solely  located  in  the  intestines,  but  all 
over  the  body,  and  the  inability  of  physiologists  to  locate  cen- 
ters for  desires  in  the  brain  is  explained. 

Whenever  the  exhibition  of  a  feeling,  or  a  feeling  itself  has 
been  destroyed  through  injury,  it  has  been  through  failure  of 
the  tracts  which  convey  molecular  movements  generated  by 
such  feelings  from  the  non-nervous  bodily  cells  wherein  these 
feelings  are  highly  developed.  The  nerves  are  pure  associa- 
tion systems,  and  where  the  feeling  aroused  in  an  organ  has 
become,  through  constant  repetition,  associated  with  certain 
other  feelings  or  with  a  motor  expression,  then  nerves  of  asso- 
ciation would  be  built  up  through  least  resistant  lines.  The 
organism  consisting  in  the  sum  total  of  the  life  activities  of  its 
cells,  the  dissociation  of  the  organism  from  its  locomotory 
organs,  the  legs,  cuts  off  the  ability  to  walk,  and  paralysis  of 
strands  leading  to  the  legs  dissociates  similarly. 

Cutting  off  the  organ  of  special  sense  or  destroying  its  tracts 
similarly  dissociate.  There  is  a  difference  between  cells  acting 
for  themselves  or  acting  unitedly  with  others. 

Returning  to  our  amoeba,  the  mobile  granules  and  molecules 
moved  with  every  impulse.  Its  sensations  were  motions  and  its 
motions  sensations,  the  two  were  inseparable.  With  a  change 


CLEVENGER — Physiology  and  Psychology. 


V 


in  the  density  of  its  ectosarc  retarding  fission  the  morula  form 
arose,  and  in  the  break  of  the  envelope  amoebae  are,  as  might 

be  expected,  liberated,  but 
they  have  inherited  this 
molecular  development  of 
ectosarc  induration  and  de- 
velop into  synamoebae  as 
did  its  parent. 

The  planeseda  developed 
cilia  through  a  similar  law. 
Owing  to  the  difficulty  of 
withdrawing  pseudopodia 
once  protruded,  these  atro- 
phied into  vibratile  organs 
through  starvation,  and  the 
hunger  motions  of  the  cells 
set  up  oscillations  of  the 
cilia,  which,  subserving  the 
life  purposes  better,  were 
perpetuated  and  the  mo- 
tions of  the  cells  adjusted 
themselves  to  the  neces- 
sity and  brought  the  envi- 
JTIG>  3  ronment  food  to  itself  by 

Gromia  oviformis,  with  its  pseudopodia  causing  eddies,  and  a  new 

extended.     From  Carpenter's   Microscopy.  Qf  locomotion  aroge 


Still,  sensation  and  motion  were  identical,  for  the  molecular 
movements  constituting  sensation  ended  in  their  develop- 
ment of  motions  into  gross  locomotory  motion,  except 
that  the  cilia  were  organs  of  locomotion  while  the  body 
remained  sensitive.  We  may  regard  the  cilium  as  formed 
dead  material  in  the  main.  Dallinger  and  Drysdales' 


24  CLEVENGER — Physiology  and  Pyschology. 

monad  rejected  it  in  eating  its  companion.  This  would 
shadow  forth  the  possibilities  of  a  set  of  ciliary  vibra- 
tions becoming  known  to  the  animal  as  tactile  locomotory, 
differing  from,  though  ministering  to,  hunger  sense,  and  a 
change  in  the  aggregation  of  the  cell  granules  would  follow. 
When  the  cell  granules  moved  in  keeping  with  the  ciliary  mo- 
tions either  the  locomotory  memory  or  act  was  aroused.  If  in 
accordance  with  hunger  movements,  then  the  memory  of 
hunger  was  aroused  and  this  could  react  upon  the  cilia  to  move 
them.  When  the  ectoderm  reached  a  stage  of  hardening  admit- 
ting of  no  more  strain  upon  it  the  central  contents  transuded 
by  some  means,  probably  temporary  rupture.  The  gaseous  and 
watery  contents  escaped  and  the  animal  collapsed  into  the 
gastraea  stage.  The  primitive  enteric  cilia  still  remain  in  the 

respiratory  tracts 
Diagram  of  an  Ovum.  as  originally  devel- 

c  a  Granular  Protoplasm.  ^  but  of  course 

b  Nucleus  (germinal  vescicle.) 

c  Nucleolus  (germinal  spot.)      changes  between 

ectodermal  and  en- 
Fig-  4-  dodermal  experi- 
ences would  differentiate  the  two  areas,  enteric  cilia  would 
be  useless  and  columnar  epithelium  would  appear.  The 
inner  remained  subject  to  constant  encounters,  or  nearly 
so,  and  the  outer  had  the  brunt  of  every  change.  The 
accelomatous  turbellaria  appear  to  me  to  be  more  of 
an  aberrent  type  not  in  our  phyllum;  many  of  the  forms 
have  undergone  much  development.  The  delamination  ori- 
gin of  the  gastrula  stage  could  be  one  of  those  onto- 
genetic  short-cuts  often  made  in  copying  phylogenesis,  the 
ends  attained  being  the  same. 

The  scolecida  or  soft  worm  presents  the  most  evident  pro- 
gress toward   development  in  the  vertebrate   direction.      Its 


CLEVENGER — Physiology  and  Psychology. 


ccelom  contains  the  first  nutrient  fluid  allied  to  blood,  but  its 
circulation  is  not  established.  The  denudation  of  the  useless 
external  cilia,  though  occasionally  developed  into  stiff  setae  in 
a  turbelarian,  follow  the  locomotory  process  changing  to  that 

characteristic  of  worms :  elongation 
and  contraction  of  the  body  length. 
Hubrecht's  newly  discovered  worm, 
the  Pscudonematon,  illustrates  this 
movement  through  the  alternate 
contraction  of  longitudinal  and  cir- 
cular muscles  with  a  plexiform 
nervous  system  between.  The  mo- 
tion is  in  some  respects  similar 
to  the  flow  of  amoeba  granules  for- 
ward into  an  arm,  but  organization 
has  restricted  this  to  a  to  and  fro 
motion.  The  shape  of  the  body 
rendering  this  the  easiest  mode  of 
progress,  the  sum  of  the  life  activi- 
ties act  in  least  resistant  lines  to  en- 
longate  and  then  contract  the 
worm.  Cause  and  effect  exchange 
places  in  the  circular  fibers  being 
placed  through  the  elongation  of 
motion  in  a  state  of  inertia,  ena- 
J3  •§  bling  the  contraction  of  the  longi- 
tudinal with  consequent  adjustment  of  the  circular  fiber  mole- 
cules so  they  contract  to  advantage.  The  repetition  of  these 
two  opposed  motions  through  the  confinement  of  the  skin 
rendering  them  about  the  only  ones  that  could  be  made,  initia- 
ted by  the  attractive  affinities  of  the  protoplasm,  finally  devel- 
oped the  contractile  tissue. 


26  CLEVENGER — Physiology  and  Psychology. 


Development  of  a  calcareous  sponge.  Olynthus.  From  Haeckel.  Showing 
the  various  stages  passed  through.  Ovum  (i),  Morula  (3),  Planula  (11), 
Gastrula  (6,  7,  8,  9,  10). 


CLEVENGER — Physiology  and  Psychology 


27 


The  ventral  location  of  the  nervous  system  in  the  errantia  or 
wandering  worms,  and  others,  is  due  to  development  through  use 
of  that  region  differentiating  locomotor  areas  from  the  epidermis, 
and  in  insecta  it  is  the  persistence  of  the  phylogenetic  origin. 

In  the  worm  stage  the  ex- 
ternal tactile  becomes 
fully  developed  through 
the  heterogeneity  of  mo- 
lar vibrations  to  which  it 
is  subjected. 

One    method    of  loco- 
motion being  possible  an- 
other is  also  possible;  dif- 
ferences   or  variations    in 

•HBBO^B^H^n* 

FIG.  7. 

The  Norwegian  Flimmerball,  (Magos- 
paaera  Planula)  swimming  by  means  of  its 
vibratile  fringes,  as  seen  from  the  surface. 
From  Haeckel. 

ment  arising  from  want  of  rigidity  in  the  worm  length. 
A  complex  of  causes  simultaneous  and  successive  operate  to 
change  the  usual  mode  of  locomotion  and  introduce  so-called 
compound  reflexes. 

The  formed  tissue  of  which  Beale  speaks  is  often  excre- 
mentitious,  and  has  through  being  useful  been  retained  by  the 
cells.  The  sandy  covering  of  the  rhizopod  Astrodiscus  arcen- 
aceus  may  have  been  "  selected  "  by  agglutination  of  the  en- 
velope with  the  particles,  or  the  shell  of  a  mollusc  may  form 
through  excretory  processes,  or  a  covering  may  be  acquired 
by  squatter  right,  as  with  the  hermit  crab.  It  matters  little  to 
the  animal.  The  fighting  cock  will  use  the  steel  gaffs  with  as 
much  gusto  as  though  they  had  grown  from  his  legs,  nor  is 
the  cell  a  particle  more  particular.  If  it  find  in  rts  environ- 


one  or  the  other,  such  as 
could  be  caused  by  me- 
chanical means,  could  re- 
sult in  a  sinuous  move- 


28  CLEVENGER — Physiology  and  Psychology. 

ment  matter  with  peculiar  properties  it  will  through  "  selec- 
tion "  eat  what  it  can  and  excrete  the  rest.  If  the  excreted 
material  have  enough  affinity  for  the  cell  to  remain  in  its  vi- 
cinity, and  a  life  process  is  subserved  by  that  fact,  things  chem- 
ical and  mechanical  in  nature  will  conspire  to  associate  the 

A 


FIG.  8. 

Testaceous  forms  of  amoeba  Rhizopods  :  A,  Difflugia  proteiformis ;  B,  Dif- 
flugia oblonga  ;  C,  Arcella  accuminata  ;  D,  Arcella  dentata.  From  Carpenter's 
Microscopy.  To  show  fortuitous  coverings  of  rhizopods. 

material  with  the  cell.  I  regard  nerve  granules,  such  as  are 
found  arranging  themselves,  or  being  arranged,  into,  first, 
plexuses  of  fibers,  and  then  definite  tracts,  as  having  arisen 
accidentally.  As  the  rhizopod  could  not  have  acquired  his 
overcoat  where  there  was  no  sand,  the  ancestral  worm  which 
picked  up  a  nervous  system  could  not  have  done  so  in  the 
absence  of  assimilable  phosphates.  The  resulting  nervous  sys- 
tem became  more  and  more  definite  in  tract  formation  as 
motions  became  more  definite  between  parts.  These  nerve 
granules  had  a  molecular  mode  of  action  altogether  different 
from  anything  experienced  before  by  the  animals.  In  higher 
forms  the  cell  substance,  which  had  the  particular  ability 
to  excrete  or  secrete  it  (relative  terms),  formed  along  the  area 
of  the  plexus  and  tracts;  next  an  encapsulating  membrane 
formed  about  it,  in  obedience  to  ordinary  physiological  and 
pathological  processes,  that  an  intermediary  substance  will  be 
attracted  and  form  around  tissues,  or  even  foreign  substances, 
as  a  resultant  of  the  mode  of  operation  of  the  two  tissues.  In 
due  time  an  area  of  nerve  granule  generation  finds  in  itself 


CLEVENGER — Physiology  and  Psychology.  29 

small  plexiform  areas,  which  are  turning  points  of  direction  for 
the  molecular  nerve  discharge ;  and  by  encapsulating  these  the 
nerve  cell  is  formed,  which  I  regard  as  having  no  other  func- 
tion than  a  histogenetic  one,  aside  from  the  molecular  impacts 
passing  through  it.  From  protoplasm  exuding  the  nerve 
granules,  the  nerve  cells  develop  to  that  office.  From  indifferent 
tissue  forming  cartilage  some  of  the  latter  form  osteal  cells. 

A  plexiform  rudimentary  nervous  system  conveys  irritations 
over  the  body.  When  the  discharges  become  definite  the  linear 
arrangement  appears,  as  in  ascidian  embryo ;  the  head  end 
developing  through  tactile  and  rudimentary  sense  organs  de- 
termining there  with  frontal  impact  of  environment.  Most 
influences  acting  to  excite  the  squirt  or  vermicular  motions 
from  mouth  to  anus,  a  method  of  locomotion  and  ingestion  at 
the  same  time. 


30  CLEVENGER — Physiology  and  Psychology. 


CHAPTER    III. 

ORGANOGENY. 

It  is  easy  to  see  how  the  mechanical  perforation  of  a  ccelen- 
terate  sac  caused  the  enteron  to  be  completed,  but  the  circu- 
latory system  origin  is  not  so  evident.  The  enterocoele  is  in 
direct  communication  with  the  enteron  in  ccelenterates,  and  the 
fluid  it  contains,  as  Huxley  says,  "  represents  blood."  It  is 
nutrient.  The  lacunae  of  some  worms  are  the  next  step  toward 
a  blood  vascular  system.  The  pseud-haemal  system  of  the 
annelida  contains  a  substance  resembling  haemoglobin;  and 
with  these  facts  before  us  we  may  construct  the  vascular  sys- 
tem and  its  workings  in  some  such  way  as  this :  The  ccelom 
is  a  receptacle  for  a  fluid  containing  nutrient  matter  which  had 
strained  through  the  endodermal  cells  and  through  interstices 
between  them.  Next  the  appearance  of  haemoglobin  or  its 
equivalent  in  the  ccelom ;  the  peculiar  properties  of  this  sub- 
stance consisted  mainly  in  its  solubility  by  alkaline  fluids  and 
its  affinity  for  oxygen,  "  which  is  linked  to  it  by  ties  so  easily 
broken  that  it  can  be  transferred  to  other  easily  oxidizable 
bodies  existing  by  its  side.  It  can  be  given  up  when  its 
solutions  are  gently  heated  in  vacuo  or  agitated  at  moderate 
temperatures  with  large  quantities  of  inactive  gases,  such  as 
nitrogen  or  hydrogen."*  This  oxygen  carrier  next  found  a 
cell  especially  adapted  to  its  transportation. 

The  red  globule  being  attracted  from  tissues  where  it  re- 
ceived oxygen  to  those  needing  it,  built  up  (by  the  identical 
processes  which  formed  the  nervous  system)  definite  passages 
*  Gamgee's  Phys.  Chem.  of  the  Animal  Body,  p.  91. 


CLEVENGER — Physiology-  and  Psychology.  3 1 

or  canals  from  indefinite  lacunae  as  soon  as  definite  attractions 
and  oxygen  furnishing  areas  arose  through  natural  selection; 
for  the  same  laws  which  govern  the  complete  organism,  save, 
develop,  and  kill  off  cells. 

In  discussing  the  cause  of  the  rythmic  contraction  of  the 
amoeba  we  surmised  for  good  reasons  it  was  the  discharge  of 
CO2  and  water,  owing  to  the  atx  orption  of  oxygen.  The  direct 
union  of  the  oxygen  causing  molecular  increase  of  bulk  in  the 
sarcode.  As  the  oxygen  is  carried  along  the  bloodvessels  simi- 
lar rythmic  pulsations  are  induced  by  the  cell  movements  in  the 
abstraction  of  oxygen.  Muscular  cells  form  around  these  ves- 
sels as  a  consequence  of  the  definite  contractions  thus  induced. 
In  veins  through  which  the  oxygen  does  not  flow,  this  would 
not  occur.  Neither  contractions  nor  development  of  muscle 
fibers.  At  first  these  motions  would  be  feeble,  but  areas  such 
as  those  in  the  Amphioxine  vessels,  where  more  oxygen  had 
been  absorbed,  either  through  the  crowding  together  of  ves- 
sels as  the  animal  shortened  its  length  (this  also  causes  the  folding 
of  the  intestines)  or  through  a  physiological  aneurism  forming 
there.  It  is  well  known  how  the  heart  forms  by  the  twisting 
upon  itself  of  the  vessel  which  forms  the  aorta.  Haeckel  * 
thinks  that  because  ascidia  have  hearts  and  amphioxus  none, 
that  the  latter  lost  it  by  reversion  and  we  inherited  it  through 
the  original  pharyngobranchii.  It  is  easier  to  suppose  that  the 
differentiation  occurred  in  a  later  stage  than  amphioxus  and 
that  the  primitive  ascidian  had  no  heart. 

^As  to  the  respiratory  development,  this  was  originally 
through  the  whole  skin  then  through  the  intestinal  tract  as  in 
all  ccelenterates  and  some  fishes;  next  the  internal  and  exter- 
nal gills  develop  more  toward  the  head  and  with  the  adapta- 
tion of  the  perennibranchiate  to  1-and  life,  and  in  some  forms 

•"'Schb^fungsgeschicte,  Vol.  II. 


32  CLEVENGER — Physiology  and  Psychology. 

before,  the  swimming  bladder  develops  the  air  cells  and  be- 
comes a  lung. 

In    the    June    25, 

1 88 1,  Science,  (N.  Y.), 
I    published    the    fol- 
lowing : 
FIG.  9. 

Cobitus  fossilu.  It  swallows  air  bubbles,  which  "There  are  many 
pass  through  the  intestines,  where  the  mucous  reasons  for  believing 
membrane  takes  up  the  oxygen  for  respiration.  that  the  thyroid  and 

thymus  are  rudimentary  gills,  one  of  the  main  objections  to 
the  view  being  the  structure  of  these  bodies;  but  in  the  light 
of  modern  biology  structure  is  almost  meaningless  in  homolo- 
gizing.  Besides  the  tissues  of  these  parts  are  not  the  same  in 
all  animals.  Owen,  Vol.  I,  p.  565,  says  the  thymus  appears  in 
vertebrates  with  the  establishment  of  lungs  as  the  main  or 
exclusive  respiratory  organ.  In  Siren  and  Proteus  the  thymus 
is  wanting,  as  in  all  fishes.  Gegenbaur,  Comp.  Anat.  p.  554, 
speaks  of  the  thyroid  as  an  organ  with  unknown  physiological 
relations,  and  that  '  in  fishes  it  is  placed  not  far  from  the  point 
at  which  it  was  formed,  that  is,  at  the  anterior  end  of  the  trunk 
of  the  branchial  artery  and  between  it  and  the  copula  of  the 
hyoid  arch ;  in  amphibia  near  the  larynx,  and  is  set  on  the 
inner  surface  of  the  posterior  cornua  of  the  hyoid.'  Gegenbaur 
considers  it  an  organ  of  use  among  Tunicata.  This  latter 
idea,  as  well  as  the  one  I  have  advanced,  needs  verification.  I 
am  unwilling  to  devote  more  time  to  the  subject  until  I  can  as- 
certain whether  some  one  has  not  preceded  me  in  announcing 
the  homology,  if  it  be  one.  Much  light  can  be  thrown  upon 
the  disease  known  as  goitre  by  clearing  up  this  point." 

Fatty  degeneration  or  conversion  into  another  tissue  is  the 
general  fate  of  the  thyroid  and  thymus.  Since  the  above  was 
published  I  am  led  to  include  the  tonsils  in  this  derivation. 
"The  foetal  lung  structure  resembles  the  thymus,  and  the 
pleura  covers  it."* 

*  Klein's  Atlas  of  Histology,  p.  244. 


CLEVENGER — Pliysiology  and  Psychology.  3  3 

The  osmotic  influence  in  respiration  I  regard  as  osmosis 
generally  should  be,  depending  mainly  upon  the  conditions 
existing  on  both  sides  of  the  membrane,  rather  than  as  having 
reference  to  any  mysterious  property  of  the  membrane  itself 
aside  from  a  peculiar  adjusted  permeability. 

This  is  the  developed  trait  and  structure  of  the  air  cell.  The 
haemoglobin  is  the  active  agent  in  effecting  respiration. 

The  lymphatic  system,  Rindfleisch  considers  as  a  receiver 
of  materials  in  excess  of  nutrition ;  hence  when  clogged  as  by 
mercury,  etc.,  there  will  be  luxurious  growths,  neoplasms  and 
catarrhs.  It  may  be  likened  to  the  original  ccelomatous  cavity, 
as  the  receptacle  of  extra  pabulum,  and  whenever  lymphatic 
hearts  exist  in  an  animal,  oxygen  must  have  been  conveyed 
through  them,  if  my  theory  be  true,  and  the  defective  oxygen- 
ation  of  the  lymph  in  man  and  such  other  animals  as  have  not 
these  hearts  point  to  the  reason  for  the  arterial  pulsations 
existing  without  similar  movements  in  other  channels.  The 
intestinal  rythm  partakes  of  this  nature.  Much  oxygen  is 
swallowed  with  food  and  abstracted  directly  by  the  intestines 
from  it,  hence  the  vermicular  motions ;  but  there  is  a  mechan- 
ical tactile  influence  also  operative  there.  This  is  the  intestinal 
locomotory  tactile  activity  perpetrated  from  the  ectodermal 
origin. 

A  lack  of  oxygen  excites  vermicular  motion,  just  as  the 
activity  of  the  amoeba  is  excited  when  it  is  hungry.  The 
complete  absence  of  oxygen  from  both  amoeba  and  intestine 
would  paralyze  the  motions.  Excess  of  CO2  excites  expul- 
sory  motions  in  both,  the  excretory  presence  having  developed 
to  expel  this  gas;  even  with  the  absence  of  much  oxygen. 
When  the  blood  is  saturated  with  oxygen  apncea  follows.  The 
plethora  of  the  molecules  stay  all  "motions  in  both  cell  and 
higher  organism  or  organ. 


34  CLEVENGER — Physiology  and  Psychology. 

"  The  size  of  the  red  blood  corpuscle  is  greater  in  the  ratio 
of  the  persistence  of  the  branchial  apparatus,  and  the  perenni- 
branchiates  or  deciduous  gilled  animals  present  the  biggest 
blood  discs  absolutely,  as  well  as  in  proportion  to  the  size  of 
the  body,  of  all  vertebrate  animals."  *  The  blood  corpuscles 
are  relatively  smaller  in  both  sides  of  the  vertebrata,  showing 
that  as  the  gills  become  less  effective  and  before  the  lungs 
were  fully  developed  the  increase  in  the  blood  disc  was  of  a 
vicariating  nature.  Prof.  Harrison  Allen  suggested  to  me  that 
this  would  admit  of  more  oxygen  to  the  disc  and  probably 
enable  it  to  be  held  longer.  The  idea  is  a  good  one.  After 
the  lungs  are  established  the  corpuscle  grows  small  again,  and 
this  fact,  with  due  consideration  of  third  causes,  which  always 
operate,  will  work  out  the  problem  of  red  blood  corpuscle 
sizes  throughout  animal  life. 

Oxygen  affinity,  from  amceba  up,  seems  to  be  the  prime 
direct  agent  in  movement.  Of  course  other  nutrient  processes 
must  be  considered,  but  they  operate  less  vehemently  and  tend 
to  facilitate  the  establishment  of  oxygen  consumption.  Given 
an  environment  in  which  the  organic  matter  finds  easy  -en- 
trance to  protoplasm,  the  activity  of  the  cell  or  cells  increases 
with  the  added  facilities  for  its  assimilation  of  pabulum  ;and  at 
the  same  time  the  oxygen  consumption  increases  with  attend- 
ant activity.  The  CO2  evolution  is  in  direct  proportion  and 
dependent  upon  this  activity.  Where,  from  an  irregular  means 
of  obtaining  oxygen,  only  erratic,  here  and  there,  cellular 
action  could  result,  with  the  passage  to  and  fro  of  oxygen 
carriers,  rythmic  to  and  fro  motions  of  rudimentary  muscle 
cells  would  develop,  and  where,  as  in  the  ascidian,  this  rythm 
became  fixed  in  a  mouth  to  anus  direction,  the  tendency 
toward  fixation  of  a  method  of  supply  of  oxygen  would  be  a 

*  Richard  Owen,  Comp.  Anatomy  and  Physiology,  vol.  I  p.  801. 


CLEVENGER — Physiology  and  Psychology.  3  5 

consequence.  This  appears  to  involve  the  constant  definite 
supply  of  oxygen  to  sphincter  muscles  while  in  tonic  contrac- 
tion, and  the  establishment  of  subsidary  arrangements  in  the 
way  of  blood  supply  to  produce  it.  Muscle  cells  would  dif- 
ferentiate with  abilities  as  widely  unlike  as  those  of  unstriped 
and  striped  aggregates.  The  striped  have  been  evolved  from 
the  unstriped.  The  former  being  under  the  control  of  the 
will  and  acting  more  promptly  over  large  extents  than  the 
unstriped.  Abilities  which  may  be  due  to  arrangements  of 
the  muscle  cells  themselves,  to  the  development  of  these 
cells,  and  to  associated  apparatus.  The  stimuli  rates  necessary 
to  contract  red  and  pale  striated  muscles  are  ten  in  the  former 
to  twenty  or  thirty  in  the  latter  per  second,  showing  that  with 
blood  increase  there  is  more  prolonged  action  for  the  same 
stimulus.  The  contraction  is  quicker  in  insects  than  frogs  ;  in 
the  heart  muscle  than  in  the  intestinal  smooth  muscle;  the 
tendency  of  differentiation  being  to  prolong  the  contraction  for 
a  similar  stimulation.  The  translocation  of  molecules  are  in 
rectangular  directions.  In  the  extension  of  an  amoebic  part  by 
attraction  (of  oxygen),  there  is  consequent  contraction  of  the 
mass  across  the  line  of  extension;  so  that  contraction  is  sec- 
ondary and  a  result  of  the  propulsion  of  particles  apart.  In  the 
expulsion  of  the  vacuole  contents  there  is  an  aggregation  in 
general  of  the  mass.  From  this  and  other  phenomena,  I  judge 
that  the  undifferentiated  cell  which  would  expand  with  the  in- 
troduction of  oxygen,  at  least  until  the  atomic  interchange  had 
been  effected,  might,  as  CO2  was  evolved  as  a  waste  product, 
then  slightly  contract.  But  with  the  differentiation  of  muscle 
cells  the  aggregative  tendency  of  the  cell  contents  implied  the 
presence  of  some  probably  crystallizable  substance,  particles  of 
which  when  oxidised  would  be  drawn  together  as  long  as  the 
temporary  oxidation  lasted.  Such  a  property  might  be  de- 


36  CLEVENGER — Physiology  aud  Psychology. 

veloped  from  haemoglobin  acquiring  attractive  qualities  when 
situated  in  muscle  precincts.  In  fact,  haemoglobin,  with  its 
peculiar  faculty  of  loosely  holding  oxygen,  could  be  thus 
developed  when  situated  axially  in  a  cell  which  constantly 
tended  to  act  in  a  certain  way,  as  the  muscle  cell  does.  A  bar 
of  iron,  if  hung  in  the  line  of  the  magnetic  meridian,  or  sub- 
jected to  frequent  concussions,  will  acquire  magnetic  proper- 
ties. It  is  the  constant  operation  of  the  law  of  adjustment 
to  circumstances.  A  cell,  a  tissue,  or  an  animal  which  acts  in 
a  certain  way  finds  that  chance  throws  in  its  path  materials  of 
which  it  can  make  use ;  and  even  these  undergo  adaptation  to 
the  constant  influence.  This  action  and  reaction  has  built  up 
the  muscle  complex.  That  oxygen  is  a  factor  in  the  contrac- 
tion is  not  disproven  under  circumstances  which  apparently, 
but  do  not  really,  cut  off  that  gas.  Englemann*  has  shown 
that  muscle  in  atmospheres  of  carbonic  acid,  carbonic  oxide, 
hydrogen,  etc.,  soon  loses  its  irritability,  but  in  oxygen  pre- 
serves it  for  a  long  time.  Apropos  of  the  tonic  contraction 
implying  a  modified  vascular  distribution  in  muscles  subject  to 
it,  "  Ranvier  demonstrated  a  peculiar  condition  of  the  minute 
veins  and  capillaries  in  the  red  muscles  of  the  rabbit,  these 
vessels  being  possessed  of  sinuous  and  spindle-shaped  dilata- 
tions, owing  probably  to  the  almost  permanent  contraction  of 
these  muscles."  f 

'  The  parallel  direction    of  the    capillaries    with    the  muscle 
fibers  is  also  significant. 

Certain  medicines,  like  ergot,    may  influence  this  oxygen- 
ating function  and  thus  exert  their  characteristic  effects. 

The  evolution  of  the  liver  is  through  certain  scattered  enteric 
cells  developing    an    ability  to  elaborate   certain   substances. 

*  Pfluger's  Archiv.  II,  1869,  243. 

4-  E.  Meyer,  quoted  by  Klein,  Atlas  of  Histology,  p.  So. 


CLEVENGER — PJiysiology  and  Psychology,  37 

Natural  selection  grouped  those  cells  in  areas  where  this  sub- 
stance was  most  likely  to  be  encountered,  and  hence  the  or- 
ganogeny  can  be  traced.  That  bile  facilitates  the  intestinal 
operations  in  my  opinion  points  to  an  adjustment  of  the  enteron 
for  that  excrementitious  substance  rather  than  that  the  liver 
was  made  to  secrete  bile  to  act  on  the  canal.  The  liver  cells 
have  an  elaborating  function  of  a  peculiar  kind  allied  to  the  gen- 
eral assimilative,  and  doubtless  other  functions  than  the  origi- 
nal have  been  added  to  the  liver  in  its  development. 

The  relativity  of  the  terms  excretion  and  secretion  is  appar- 
ent in  the  complementary  functions  developed  by  cells.  In 
the  greedy  absorption  altruism  or  generosity  is  absolutely  ab- 
sent, and  what  one  cell  cannot  take  up  goes  to  another.  In  cell 
excretion  substances  are  changed  more  or  less,  and  a  contigu- 
ous cell  must,  if  situated  so  it  cannot  reach  the  food  direct,  put 
up  with  such  excreted  matter.  It  adjusts  itself  to  that 
sort  of  food  and  in  time  cannot  survive  on  any  other. 
Due  consideration  of  this  will  account  for  the  multi- 
tude of  chemical  combinations  in  the  fluids  and  tissues 
of  the  body. 

An  ethological  deduction  is  not  out  of  place  here.  Each 
ciliated  cell  whips  the  environment  to  bring  itself  food  ;  it  cares 
nothing  for  its  neighbor,  nor  is  it  grateful  to  the  preceding 
cells  which  aided  it  in  starting  the  circulation.  This  egoism 
or  selfishness  is  that  of  the  chemical  elements  which  grab  where 
they  can,  but  in  high  development  the  organism  sees  that  others 
are  benefited  by  its  egoistic  acts  and  instantly  deliberates  how 
to  turn  this  to  account.  It  suggests  that  as  its  neighbor  has 
derived  an  advantage  from  this  act  some  sort  of  recompense 
is  due,  and  where  nothing  more  substantial  is  obtainable 
gratitude  is  demanded,  which  is  merely  a  generalization  for  the 
disposition  to  requite  favors  in  the  future ;  to  pay,  when  the 


38  CLEVENGER — Physiology  and  Psychology. 

opportunity  arises.     Our  reprehension  of  ingratitude  is  in  the 
abhorrence  of  not  granting  the  quid  pro  quo. 

The  adjustment  of  cells  to  certain  media  may  entail  the  ne- 
cessity for  the  continuance  of  the  presence  of  substances  even 
after  having  left  the  medium  in  which  the  adjustment  was  ac- 
quired. For  instance,  the  desire  for  salt  with  food  in  excess  of 
that  furnished  by  the  food,  indicates  the  piscine  adjustment ; 
and  the  presence  of  salines  in  the  fluids  evidence  the  omni- 
prevalence  of  this  cell  adjustment.  Some  savages  and  animals 
have  acquired  a  disrelish  for  salt  through  circumstances  develop- 
ing that  disrelish,  such  as  absence  of  the  article  from  the  coun- 
try lived  in,  or  ignorance  of  the  mineral  as  found  on  land  par- 
taking of  the  nature  of  that  to  which  the  marine  ancestor  was 
accustomed.  Nevertheless  a  modicum  is  always  taken  in  with 
the  vegetable  or  animal  food. 

Some  of  the  changes  wrought  by  the  erect  posture  following 
the  previous  quadrupedal,  were  noted  by  me  in  the  subjoined 
which  was  published  in  the  American  Naturalist  January,  1884. 
The  substance  of  the  article  entitled  "  Disadvantages  of  the  Up- 
right Position,"  I  read  before  the  University  Club  of  Chicago, 
April  18,  1882: 

The  immediate  and  remote  causes  of  things  have  been  and 
will  be  sought  by  thinkers  who  are  not  afraid  to  follow 
wherever  facts  lead  them.  The  doctrine  that  there  is  no  effect 
without  an  antecedent  cause,  has  met  with  fierce  opposition 
from  those  who  saw  that  the  logical  conclusions  of  correlated 
facts,  such  as  are  presented  by  Darwin,  tended  to  the  over- 
throw of  puerile  legends  they  believed  in,  and  who  were  con- 
tent to  imagine  that  everything  was  causeless,  or,  at  best,  orig- 
inated in  some  inscrutable  way.  The  Arab,  upon  having  the 
sidereal  motions  explained  to  him,  said,  "  You  trouble  your- 
self greatly  about  things  not  intended  for  you  to  know.  Even 
though  what  you  tell  me  is  true,  the  Koran  leads  us  to  believe 


CLEVENGER — Physiology  and  Psychology.  39 

otherwise.  Mohammed  taught  us  sufficient,  and  his  followers 
can  torture  you  out  of  your  rationalism.  Forbear  your  heret- 
ical facts ! " 

The  mechanical  nature  of  things  animate  is  as  old  in  theory 
as  Democritus,  500  B.  C. ;  and  Giordano  Bruno,  in  A.  D. 
1600,  for  having  amplified  the  Democritic  idea,  was  burned  at 
the  stake.  Kant  granted  a  mechanical  cosmogony,  but  in 
organic  nature  claimed  causes  finales.  The  battle  of  causce 
cfficientes  was  fully  won  by  Galileo,  Copernicus,  Kepler,  New- 
ton, Herschel,  Laplace,  etc.,  so  far  as  the  inanimate  universe 
was  concerned,  but  the  mechanical  conception  of  that  which 
pertains  to  living  things  was  hinted  at  by  Aristotle.  Geoffrey 
de  St.  Hilaire  contended  against  Cuvier  for  the  mutability  of 
species  and  the  monistic  theory.  Treviranus,  Oken,  Goethe, 
Lamarck,  and,  in  our  day,  Darwin,  Haeckel,  Huxley,  have 
carried  on  the  warfare.  Herbert  Spencer  advanced  a  mechan- 
ical physiology  and  morphology.  His  has  carried  the  con- 
ception into  histology,  and  Cope  into  palaeontology.  The 
unity  of  the  laws  which  control  organic  and  inorganic  nature 
are  to-day  fully  recognized  by  those  who  stand  in  the  front 
rank  of  investigators  and  thinkers,  but  not  until  completer  text- 
books from  the  new  standpoint  shall  have  found  their  way  into 
the  hands  of  medical  students  and  naturalists  generally,  will 
common  recognition  of  the  success  of  the  mechanical  idea  be 
obtained. 

Assuredly,  the  teleological  is  a  very  lazy  way  of  thinking. 
It  amounts  to  taking  things  for  granted  as  so,  because  they 
are  so.  It  bars  all  inquiry,  stops  all  investigation,  and  hands 
us,  bound  hand  and  foot,  to  ignorance  and  superstition. 

Mechanical  influences,  such  as  impacts  and  strains,  perma- 
nently altering  animal  organs  have  been  discussed  by  Pro- 
fessor E.  D.  Cope  in  the  American  Naturalist,  in  articles  en- 
titled, Origin  of  the  Foot  Structures  of  Ungulates,  April,  1881 ; 
Effects  of  Impacts  and  Strains  on  the  Feet  of  Mammalia, 
July,  1 88 1  ;  by  Alpheus  Hyatt,  Transformations  of  Planorbis 
at  Steinheim,  with  Remarks  on  the  Effects  of  Gravity  upon  the 
forms  of  Shells  and  Animals,  June,  1 882.  In  articles  published 


4O  CLEVENGER — Physiology  and  Pyschology. 

in  the  January  and  February,  1881,  numbers,  I  attempted  a 
disquisition  upon  physical  influences  in  their  relations  to  com- 
parative neurology,  and  in  the  July,  188 1,  number  of  the 
American  Naturalist,  On  the  Origin  and  Descent  of  the  Hu- 
man Brain,  pointed  out  some  hitherto  neglected  mechanical 
factors  in  the  development  of  the  organ  of  the  mind  and  its 
osseous  envelope. 

While  engaged  in  anatomical  studies,  the  idea  that  there 
was  a  definite  reason  for  everything,  and  that  we  might  some 
day  discover  the  reasons  for  many  things  not  now  known,  was 
ever  present  to  my  mind.  I  could  get  half  lights  and  glimpses 
of  causes  from  hints  in  Henle,  H olden,  or  Sharpey  and 
Quain,  and  fancied  I  saw  matters  clearly  enough  in  some  par- 
ticulars, only  to  be  confused  by  contradictory  experiences  sub- 
sequently. 

There  seemed  to  be  a  definite  enough  law  in  the  formation 
of  valves  in  the  veins,  for  instance,  but  every  student  was  com- 
pelled to  learn  the  location  of  these  valves  by  arbitrary  exer- 
cise of  the  memory.  I  think  that  every  student  will  conclude 
at  the  end  of  this  paper  that  it  is  easy  enough  now  to  remem- 
ber which  veins  are  valved  and  which  are  not.  Let  me  present 
the  subject  just  as  it  perplexed  me  at  first  Nothing  could  be 
simpler  from  the  teleological  standpoint,  than  that  we  should 
have  valves  in  the  veins  of  the  arms  and  legs  to  assist  the  re- 
turn of  the  blood  to  the  heart  against  gravitation,  but  what 
earthly  use  has  a  man  for  valves  in  the  intercostal  veins  which 
carry  blood  almost  horizontally  backward  to  the  azygos  veins  ? 
When  recumbent,  these  valves  are  an  actual  detriment  to  the 
free  flow  of  blood.  The  inferior  thyroid  veins  which  drop  their 
blood  into  the  innominate  are  obstructed  by  valves  at  their 
junction.  Two  pairs  of  valves  are  situated  in  the  ex- 
ternal jugular  and  another  pair  in  the  internal  jugular, 
but  in  recognition  of  their  uselessness  they  do  not  pre- 
vent regurgitation  of  blood  nor  liquids  from  passing  up- 
wards. 

An  apparent  anomoly  exists  in  the  absence  of  valves  from 
parts  where  they  are  most  needed,  such  as  in  the  venae  cava, 


CLEVENGER — Physiology  and  Psychology.  41 

spinal,  iliac,  haemorrhoidal  and  portal.    The  azygos  veins  have 
imperfect  valves. 

Place  man  upon  "  all  fours  "  and  the  law  governing  the  pres- 
ence and  absence  of  valves  is  at  once  apparent,  applicable,  so 
far  as  I  have  been  able  to  ascertain,  to  all  quadrupedal  and 
quadrumanous  animals  :  Dorsad  veins  are  valved ;  cephalad, 
vcntrad  and  caudad  veins  have  no  valves.  The  apparent  ex- 
ceptions to  this  rule,  I  think,  can  be  disposed  of  by  considering 
the  jugular  valves  as  obsolescing,  rendered  rudimentary  in  man 
by  the  erect  head,  which  in  the  lemur  stage  depended.  The 
rudimentary  azygos  valves  may  be  a  recent  creation,  and  an 
explanation  of  their  presence  may  be  found  in  the  mutability 
of  the  cardinal  system.  The  azygos  veins  are  derived  from 
the  intercostal,  and  the  rudimentary  valves  may  be  a  remnant 
of  the  original  condition.  The  single  Eustachian  valve,  being 
large  in  the  foetus,  has  a  phylogenetic 
value. 

The  only  reason  I  can  assign  for  the 
absence  of  cephalic  and  cervical  valves 
generally,  while  the  jugulars  possess 
them,  is,  that  the  jugular  system  was 
the  most  important  to  our  quadrupedal 
ancestors  with  dependent  heads,  hence 
valves  developed  in  them,  and  owing 
to  the  cranial  blood  vessels  developing, 
part  passu,  with  the  cranium  and  its 
contents  generally,  largely  after  man 
had  assumed  the  erect  position,  the 
valvular  formation  elsewhere  in  the 
head  would  not  occur  while  the  jugu- 
lar valves  became  rudimentary. 

Certainly  valves  in  the  haemor- 
rhoidal veins  would  be  out  of  place 
in  quadrupeds,  but  to  their  absence  in 
man  many  a  life  has  been  and  will  be 

a,  infers  to  the  spinal  sys-  sacrificed,"  to  say  nothing  of  the  dis- 
tem ;  *,  jugular  and  cayal  to  comfort  and  distress  occasioned  by  the 

femoral;  c,  brachial ;  d,  inter-  1-1 

costal.  engorgement   known   as   piles,  which 


42  CLEVENGER — Physiology  and  Psychology. 

the  presence  of  valves  in  these  veins  would  obviate.  The 
spermatic  valves  are  as  useful  in  man  as  in  other  animals. 

A  glance  at  the  accompanying  diagram  will  afford  an  idea 
of  the  confusing  distribution  of  valved  and  unvalved  veins 
in  the  human  being. 

The  position  assumed  by  these  valved  veins  when  man 
is  placed  on  all  fours,  corresponds  with  those  to  be  found 
in  quadrupeds,  thus : 


A  noticeable  departure  frorA  the  rule  obtaining  in  the 
vascular  system  of  Mammalia  also  occurs  in  the  exposed 
situation  of  the  femoral  artery  in  man.  The  arteries  lie 
deeper  than  the  veins,  or  are  otherwise  protected  for  the  pur- 
pose, the  teleologist  would  say,  of  preventing  haemorrhage  by 
superficial  cuts.  From  the  evolutionary  standpoint  it  would 
appear  that  only  animals  with  deeply-placed  arteries  would 
survive  and  transmit  their  peculiarities  to  their  offspring,  as 
the  ordinary  abrasions  to  which  all  animals  are  subject,  not  to 
mention  their  fierce  onslaughts  upon  one  another,  would 
quickly  kill  off  animals  with  superficially  located  arteries. 
But  when  man  assumed  the  upright  posture,  the  femoral 
artery,  which  was  placed  out  of  reach  on  the  inner  part  of  the 
thigh,  became  exposed,  and  were  it  not  that  this  defect  is 
nearly  fully  atoned  for  by  his  ability  to  protect  the  exposed 
artery  in  ways  the  brute  could  not,  he  too  would  have  become 
extinct.  Even  as  it  is,  this  aberration  is  a  fruitful  cause  of 
trouble  and  death. 

Another  disadvantage  which  occurs  in  the  upright  position 


CLEVENGER — Physiology  and  Psychology  43 

of  man,  is  his  greater  liability  to  inguinal  hernia.  Quadrupeds 
have  the  main  weight  of  abdominal  viscera  supported  by  ribs 
and  strong  pectoral  and  abdominal  muscles.  The  weakest 
part  of  the  latter  group  of  muscles  is  in  the  region  of  Poupart's 
ligament,  above  the  groin.  Inguinal  hernia  is  rare  in  other 
vertebrates  because  this  weak  part  is  relieved  of  the  visceral 
stress,  but  as  the  pelvis  receives  the  intestinal  load  in  man,  an 
immense  number  of  trusses  are  manufactured  to  supplement 
this  deficiency.  It  has  been  estimated  that  twenty  per  cent,  of 
the  human  family  suffer  in  this  way,  and  strangulated  hernia 
frequently  occasions  death. 

If  man  has  always  been  erect  from  creation,  then  we  have 
nothing  to  hope  from  the  future  by  way  of  an  alteration  of  this 
defect.  The  same  percentage  of  humanity  will  suffer  to  the 
end  of  time ;  but  considered  mechanically  the  so-called  con- 
servative influence  of  nature  which  will  tend  to  pile  up 
additional  muscular  tissue  in  this  region  by  reason  of  the 
increased  blood  supply  to  that  part,  aided  by  natural  and 
sexual  selection,  will  eventually  reduce  the  percentage  of 
ruptures  greatly,  if  it  does  not  finally  correct  the  trouble 
altogether.  The  liability  to  femoral  hernia  is  similarly 
increased  by  the  upright  position. 

The  peritoneal  ligaments  of  the  uterus  subserve  suspensorial 
functions  in  quadrupeds  fully,  which  requires  much  ingenious 
speculation  to  be  faintly  seen  in  man.  The  anterior,  posterior 
and  lateral  ligaments  are  mainly  concerned  in  preventing  the 
gravid  uterus  from  pitching  too  far  toward  the  diaphragm  of 
four-footed  animals.  The  round  ligaments  are  absolutely 
meaningless  in  the  human  female,  but  in  lower  animals  serve 
the  same  purpose  as  the  other  ligaments.  Prolapses  uteri,  by 
the  erect  position  and  absence  of  support  fitted  to  that  attitude, 
are  thus  rendered  frequent,  to  the  destruction  of  health  and 
happiness  of  multitudes. 

As  a  deduction  from  mechanical  laws,  it  could  easily  be  im- 
agined that  an  animal  or  race  of  men  which  had  the  longest 
maintained  the  erect  position  would  have  straighter  abdo- 
mens, widely  flared  pelvic  brims  with  contracted  pelvic  outlets, 


44  CLEVENGER — Physiology  and  Psychology. 

and  that  the  weight  of  the  spinal  column  would  carry  the  sac- 
rum lower  down,  and  in  general  terms  we  find  this  to  be  the 
case.  In  quadrupeds,  the  box-shaped  pelvis,  which  admits  of 
easy  parturition,  prevails,  but  where  the  position  of  the  animal 
is  such  as  to  throw  the  weight  of  the  viscera  into  the  pelvis, 
the  brim  necessarily  widens,  these  weighty  organs  sink  lower, 
and  the  heads  of  the  femora,  acting  as  fulcra,  admit  of  the  crest 
of  the  ilium  being  carried  outward,  while  the  lower  part  of  the 
pelvis  must  be  contracted.  This  box  shape  exists  in  the 
child's  innominate  bones,  while  its  protruding  abdomen  resem- 
bles that  of  the  gorilla.  The  gibbon  exhibits  this  iliac  expan- 
sion through  the  sitting  posture,  which  developed  his  ischial 
callosities.  Similarly  iliac  expansion  occurs  in  the  chimpan- 
zee. The  Megatherium  had  wide  iliacal  expansion,  due  to  its 
semi-erect  habits,  but  as  its  weight  was  mainly  supported  by 
the  huge  tail  with  femora  resting  in  acetabula  placed  far  for- 
wards, the  leverage  necessary  to  contract  the  lower  pelvis  is 
absent.  Professor  Weber,  of  Bonn,  noted  by  Carl  Vogt,  "  Vor- 
lesungen  uber  den  Menschen™  etc.,  distinguished  four  chief 
forms  of  the  pelvis  in  man :  the  oval,  round,  square  and  cunei- 
form, owned  in  order  by  Europeans,  native  Americans,  Mon- 
gols and  black  races.  Resting  upon  its  own  merits  as  an  osse- 
ous mechanical  proposition,  it  would  seem  that  the  older  the 
race  the  lower  the  sacrum  and  the  greater  the  tendency  to  ap- 
proximate the  larger  transverse  diameter  of  the  European  fe- 
male. The  anteroposterior  diameter  of  the  simian  pelvis  is 
usually  greater  than  the  transverse  ;  a  similar  condition  affords 
the  cuneiform,  from  which  could  be  inferred  that  the  erect  po- 
sition in  the  negro  races  had  not  been  so  long  maintained  as 
by  the  Mongols,  whose  pelvis  assumed  the  quadrilateral  shape 
owing  to  persistence  of  spinal  axis  weight  through  greater 
time;  this  pressure  has  finally  culminated  in  pressing  the 
sacrum  of  the  European  nearer  the  pubes,  with  consequent 
lateral  expansions  at  the  expense  of  the  antero-posterior  or  con- 
jugate. From  Marsupialia  to  Lemuridae  the  box  shape  pelvis 
persists,  but  with  the  wedge  shape  induced  in  man  a  re- 
markable phenomenon  also  occurs  in  the  increased  size  of  the 


CLEVENGER — Physiology  and  Psychology.  45 

foetal  head  in  disproportion  to  the  contraction  of  the  pelvic 
outlet.  While  the  marsupial  head  is  about  one-sixth  the  size 
of  the  smallest  part  of  the  parturiant  bony  canal,  the  moment 
we  pass  to  erect  animals  the  greater  relative  increase  is  there 
in  the  cranial  size  with  coexisting  decrease  in  the  area  of  the 
outlet.  This  altered  condition  of  things  has  caused  the  death 
of  millions  of  otherwise  perfectly  healthy  and  well-formed  hu- 
man mothers  and  children.  The  palaeontologist  might  tell  us 
if  some  such  phenomenon  of  ischial  approximation  by  natural 
mechanical  causes  has  not  caused  the  probable  extinction  of 
whole  genera  of  vertebrates. 

If  we  are  to  believe  that  for  our  original  sin  the  pangs  and 
labor  at  term  were  increased,  and  also  believe  in  the  dispro- 
portionate contraction  of  the  pelvic  space  being  an  efficient 
cause  of  the  same  difficulties  of  parturition,  the  logical  infer- 
ence is  inevitable  that  man's  original  sin  consisted  in  his  get- 
ting upon  his  hind  legs. 

Something  of  the  changes  noticed  in  the  angle  at  which  the 
head  of  the  femur  in  set  upon  the  shaft  at  different  ages,  is  also 
noticeable  phylogenetically.  The  neck  of  the  femur  in  the 
child  is  obliquely  placed,  but  in  the  adult  is  less  so,  and  in 
advanced  age  tends  to  form  a  right  angle  with  the  socket. 
Both  in  the  advance  of  age  in  the  individual  and  the  tendency 
of  an  animal  to  assume  more  and  more  the  upright  posture, 
this  change  of  angle  seems  attributable  to  no  other  cause  than 
bodily  weight  against  the  femoral  heads. 

This  subject  is  not  without  direct  application.  Gynaecolo- 
gists cause  their  patients  to  assume  what  is  called  the  knee 
chest  position,  a  prone  one,  for  the  purpose  of  restoring  uteri 
to  something  near  a  natural  position.  Brown-Sequard  recom- 
mends drawing  away  the  blood  from  the  spine  in  myelitis,  or 
spinal  congestion,  by  placing  the  patient  on  his  abdomen  or 
side  with  hands  and  feet  somewhat  dependent.  The  liability 
to  spina-bifida  is  greatest  in  the  human  infant  through  the 
stress  thrown  upon  the  spine,  and  the  absence  of  delivery 
troubles  among  lower  races  have  reference  to  discrepancy 
between  pelvic  and  cranial  sizes  not  having  been  reached  by 


46  CLEVENGER — Physiology  and  Psychology. 

those  races.  The  Sandwich  island  mother  has  difficult  delivery 
only  when  her  progeny  is  half  white,  that  breed  being  larger 
in  the  forehead  than  the  native  child. 

Dr.  Crichton  Brown  notes  in  West  Riding  Asylum  Reports 
that  a  great  number  of  insane  cases  originated  through 
disasters  directly  due  to  cranial  and  pelvic  discordances  at 
child  birth. 

The  mechanism  of  the  body,  when  fully  recognized  as 
mechanism  and  nothing  else,  and  as  governed  by  mechanical 
laws,  physical  as  well  as  chemical  influences,  will  place  forth- 
coming physiological  studies  upon  a  broader,  safer  foundation, 
and  result  in  grand  generalizations.  The  hydro-dynamics  of 
animal  life  would  alone  furnish  a  theme  for  thousands  of 
investigators.  At  present  the  world  goes  on  in  its  blindness, 
apparently  satisfied  that  everything  is  all  right  because  it 
exists  at  all,  ignorant  of  the  evil  consequences  of  apparently 
beneficent  peculiarities,  vaunting  man's  erectness  and  its 
advantages,  while  ignoring  the  disadvantages.  The  observation 
that  the  lower  the  animal  the  more  prolific,  would  eventuate 
the  belief  that  the  higher  the  animal  the  more  difficulties 
encompass  his  development  and  propagation,  and  the  cranio- 
pelvic  incompatibility  alone  may  settle  the  Malthusian  doctrine 
effectually  for  the  higher  races  of  men  through  their 
extinction. 


CLEVENGER — Physiology  and  Psychology, 


47 


CHAPTER   IV. 


GENESIS. 


Herbert  Spencer*  thus  tabulates  the  relations  existing  among 
the  different  modes  of  genesis  : 

(Oviparous 
or 
Ovoviviparous 
or 

(^    Viviparous 
f  Gamogenesis    f    Parthenogenesis 


Genesis  \ 


I    Alternating 
or  with 

Heterogenesis    [  Agamogenesis 


Pseudoparthenogeneis 
or 

( Internal 
Metagenesis  <        or 

I  External 


Spencer  quotes  (ibid)  Professor  Huxley's  classification  which 
makes  every  kind  of  genesis  a  mode  of  development. 


Development 


Continuous 


f  Growth 

'(  Metamorphosis. 


f  Agamogenesis     f  Metagenesis 
Discontinuous     ( Gamogenesis.      ( Parthenogenesis. 


The  Spencerian  and  Huxley ian  schemes  may  be  put  into 
simple  language  thus : 


(Genesis) 
Breeding  is  through 


Similar  to  Parent  form  which    is  from  f  From  the  Egg 


Sexual  Union 
(Homogenesis)  (Gamogenesis) 

From  sexual  union 
(Gamogenesis) 


Different    from 
the  Parent 

(Heterogenesis) 


Alternating  with 
Breeding  without  Pre- 
vious Sexual  Union 
(Agamogenesis) 


(oviparous) 

or 

From  the   Egg  and 
bornalive 
(Ovoviviparous) 

or 
Born  alive 

(Viviparous) 
Born    from    regular 
generative    apparatus 
without  previous  sex- 
ual union  of  parents 
(.  Parthenogenesis ) 

or 

Similarly    from    non- 
differentiated     gener- 
ative apparatus 
( Pseudo-  Parthenogen  - 
esis) 

or 

f  From      the 
I      outside 
j  Budding  •{          or 

I  From      the 
I     inside. 


*  Principles  of  Biology,  Vol.  I,  p.  215. 


4$  CLEVENGER — Physiology  and  Psychology. 

f 

col-  |      (By 
ral  j  of  cells. 


Development 


Continuous.  f  Growth 

[As  in  the  formation  of  a  col-  |      (By   mere   quantitative    increase 
ony  such  as  the  sponge,  the  coral  j  of  cells.)  or 

aggregates      in     the      individual  1  Metamorphosis 

which  is  made  up  of  a  lot  of  cells         (By  radical  change  in  the  char- 
bound  together  (and  in  a  certain  [acteristic  of  the  cells.) 


sense  Society,  Nations,  the  Earth 
and  the  Universe.)] 
Discontinuous. 

(As  when  the  Amoeba  throws 
off  and  excretes  individuals  or 
individuals  give  birth  to  individ- 
uals.) 


f  Metagenesis 

Without  sexual  J  Parthenogenesis 
union.  j    (as  explained 


Through  sexual 


[         above.) 


union. 


We  considered  the  pure  relativity  of  the  matter  of  sex  in 
low  forms.  This  relativity  could  be  extended  to  atomic  combi- 
nations. The  germ  molecules  differing  from  the  sperm  mole- 
cules through  differentiation  of  the  latter,  the  formation  of  H2  O 
may  without  much  stretch  of  the  imagination  be  taken  to 
represent  the  preponderance  of  quantity  in  the  hydrogen  to 
represent  the  germ  molecule,  and  in  the  heightened  activity  of 
oxygen  the  single  but  relatively  more  chemically  important 
atom  will  represent  the  sperm  cell.  In  the  amceba  simple  fis- 
sion is  the  starting  point  for  animal  life,  and  this  being  a  pro- 
duct or  consequence  of  growth,  it  matters  nothing  whether 
that  growth  was  obtained  by  a  cannabalistic  act  or  by  ordinary 
assimilation  of  other  organic  matter.  The  synamceba  being 
developed,  as  hinted,  naturally,  by  accidental  hardening  of  the 
ectosarc,  the  rupture  of  the  envelope  liberates  amcebiform  off- 
spring (at  this  stage  heterogenetic)  which  subsequently  develop 
into  synamcebae  (then  homogenetic.) 

The  amceba  would  be  agamogenetic  if  its  fission  followed 
from  growth  either  through  assimilation  of  food  or  of  another 
amceba.  But  suppose  the  swallowed  amoeba  to  differ  from  the 
cannibal.  If  inferiorly,  the  product  could  not  be  otherwise  than 
am&bcz.  If  superiorly,  the  product  could  not  be  otherwise  than 
a  higher  type  of  amceba  or  resemble  its  parent,  because  the 
differentiated  tissue  of  the  higher  type  would  reappear  in  the 
offspring  or  would  not  reappear  in  some  of  them.  Here,  then, 
we  have  indifferently  agamogenesis  resulting  always  in  homo- 


CLEVENGER — Physiology  and  Psychology. 


49 


genesis,  and  the  same  individual  capable  of  the  gamogenetic 
act  (not  differentiated  from  the  assimilative  act)  developing 
through  definite  laws  and  for  evident  reasons  either  through 
homogenesis  or  heterogenesis. 


FIG.  10. 

A,  Encysted  statospore ;  B,  Incipient  formation  of  the  swarm  spores,  shown 
at  C  escaping  from  the  cyst,  at  D  swimming  freely  by  their  flagellate  append- 
ages, and  at  E  creeping  in  the  amoeboid  condition ;  F,  Fully  developed  reticulate 
organism,  showing  numerous  vacuoles,  a,  and  captured  prey,  b,  c.  From  Car- 
penter's Microscopy. 

In  the  morula(synamcebic)  form,  which  is  at  first  heteroge- 
netic  and  the  offspring  develop  homogenetically,  a  teratological 
influence  such  as  a  reversion  to  the  softer  ectosarc  of  the 
amoebic  ancestor  would  bring  about  "  arrested  development " 
and  result  in  that  instance  in  heterogenesis.  which  is  the  rule 
in  all  monstrosity  production. 

4 


50  CLEVJENGER — Physiology  and  Psychology. 

I  incline  to  the  belief  that  we  are  not  to  regard  the  planula 
and  gastrula  stages  as  otherwise  than  consequences  of  the 
synamceba  stage,  and  hence  the  relationship  of  these  stages  are 
closer  than  might  otherwise  be  supposed. 

Metagenesis,  which  is  usually  agamogenesis,  from  no  special- 
ized part  of  the  parent,  is  necessarily  heterogenetic,  for  it  in- 
volves a  reversion  toward  the  less  perfect  style  of  reproduction. 
Even  though  the  gamogenetic  act  preceded  the  appearance  of 
this  method  of  heterogenesis,  it  had  not  influenced  the  product, 
and  hence  metagenesis  may  be  said  to  be  agamogenetic  always. 
The  external  budding  in  most  cases  of  metagenesis  point  to  a 
faulty  direction  toward  the  paternal  tissue  and  suggest  a  cause 

t 

for  the  heterogenesis.  Sexes  being  relative  in  very  low  stages, 
the  ectodermal  budding  appears  as  a  developed  remnant  of  the 
stage  when  the  organism  was  relatively  a  female  and  the  endo- 
dermal  less  differentiated  cell  could  not  influence  it  in  this 
higher  stage.  Where  metagenesis  is  internal  it  is  a  pure  re- 
version, as  might  be  expected  in  entozoa,  such  as  the  Distoma. 

Parthenogenesis,  which  is  agamogenesis  carried  on  in  a 
sexual  organ,  is  the  same  thing,  with  the  difference  of  the  de- 
velopment of  special  cells  differentiating  from  the  general  cell 
mass  as  best  able  to  furnish  both  the  ectodermal  and  endoder- 
mal  peculiarities.  Von  Siebold  restricts  this  to  the  exclusion 
of  a  similar  process,  which  Spencer  designates  as  pseudo-par- 
thenogenesis, and  which  Huxley  claims  is  from  pseud-ova  and 
not  true  ova.  This  is  the  stage  intermediate  between  metagene- 
sis and  true  parthenogenesis,  and  may  be  a  reversion  from  the 
latter  or  a  development  from  the  former.  It  is  the  transition 
period  for  the  establishment  of  the  higher. 

With  the  advent  of  genesis  by  division  of  the  amoeba  the 
product  may  be  AAAA  with  a  developmental  reason  for  the 
occasional  introduction  of  B.  Now  this  sort  of  reproduction 


CLEVENGER — Physiology  and  Psychology.  5 1 

may  be  brought  about  by  a  change  in  diet.  A  new  form  of 
amoeba  may  originate  from  primitive  though  peculiar  chemical 
conditions  made  possible  by  a  change  of  environment,  thus 
bringing  about  a  temporary  or  permanent  change  of  the  tis- 
sues, and  I  doubt  not  many  cases  of  species  origination,  such 
as  che  short  legged  sheep  Darwin  mentions  and  sub-varieties  of 
animals  originated  embryologically.  This  phase  of  progress 
by  natural  selection  acting  upon  the  parent  cell  is  afforded  in 
the  development  of  the  queen  bee  through  change  of  food.  It 
shows  that  even  in  high  forms  the  classification  of  Huxley  is  jus- 
tified, and  tfyat  means  of  development  originally  acting  through 
the  environment  may  still  be  brought  to  bear  upon  the  ovum. 

The  step  from  AAA  with  fortuitous  B.  Homogenesis,  with 
occasional  heterogenesis  in  an  evolutionary  way,  will  be  to 
BAAAA  by  reversion  and  with  A  developing  subsequently 
like  the  parent.  The  product  of  relative  male  B  by  relative 
female  A,  would  be  either  A  or  B,  just  as  the  cell  elements  of 
either  parent  predominated.  The  product  of  agamogenetic 
B  would  be  either  A  or  B,  or  A  first  developing  into  B.  (The 
intermediate  and  lowest  stages  must  be  passed  through.)  The 
product  of  gamogenetic  B  with  C  would  be  either  B  or  C,  or, 
by  reversion,  A. 

Metagenesis  in  A  is  impossible;  in  B  would  be  identical 
with  its  usual  mode  of  increase,  i.  e.,  A,  when  agamogenetic, 
but  when  gamogenetic  with  C,  the  relative  male.  Then 
metagenesis  by  persistence  of  relative  male  attributes  of 
ectoderm  would  produce  B,  the  previous  A  stage  being  inevita- 
ble. The  pathological  dermoid  cysts  are  explained  by  this. 

Relative  female  C  with  relative  male  D  could  thus  produce 
C  or  D,  etc. 

The  occasional  appearance  of  hefmaphrodism  can  be  ac- 
counted for  by  remembering  that  every  product  of  A  and  B, 


52  C  LEVENGER — Physiology  and  Psychology. 

B  and  C,  must  have  inherited  some  of  the  elements  of  both 
The  presence  of  rudimentary  sexual  organs  in  both  male  and 
female  attests  this.  Where,  by  a  fault,  some  of  the  organs 
peculiar  to  the  other  sex  have  not  atrophied  but  have  main- 
tained a  certain  stage  of  development,  hemaphrodism  is  the  re- 
sult In  speaking  of  the  relativity  of  sex  in  organisms,  as  soon 
as  differentiation  fixes  the  sexual  organs  so  that  intromission 
is  possible  only  in  one  way,  this  relativity  gives  way  to  absolute 
sex,  though  as  regards  other  organs  and  even  mental  traits  it 
still  holds  good. 

Darwin's  theory  of  pangenesis  is  worth  repeating  here  as  a 
provisional  hypothesis  in  explanation  of  heredity.  It  assumes 
that  the  various  cells  throughout  the  body  throw  off  minute 
granules  called  gemmules,  which  circulate  freely  through  the 
body  and  multiply  by  subdivision.  These  gemmules  collect 
in  the  reproductive  organs  and  products,  or  in  buds,  when  that 
mode  of  reproduction  obtains ;  so  that  the  egg  or  bud  contains 
gemmules  from  all  parts  of  the  parent  or  parents,  which  in  de- 
velopment give  rise  to  cells  in  the  offspring  similar  to  those 
from  which  they  were  given  off  in  the  parent.  It  is  also  as- 
sumed that  these  gemmules  need  not  in  all  cases  develop  into 
cells,  but  may  be  transmitted  from  generation  to  generation 
without  producing  visible  effect  until  a  case  of  atavism  appears. 

The  amoeboid  cell  A  may  pass  to  a  morula  stage  through  ec- 
tosarcal  change  similar  to  that  of  the  synamceba.  It  will  throw 
off  A  and  B  cells,  both  containing  attributes  of  the  parents, 
though  in  differing  degrees;  the  essential  change  being  pe- 
culiarities of  the  ectodermal  forming  cell  acquired  by  an  endo- 
dermal  one. 

Aa,  Ab,  Ba,  Bb,  may  represent  the  preponderating  influence 
of  the  relative  sexes.  Certainly  the  product  of  B  is  A,  with  a 
tendency  to  form  B,  and  in  its  embryo  condition  may  be  called 


CLEVENGER — Physiology  and  Psychology.  5  3 

ovular,  and  as  containing  inherent  molecular  possibilities  ac- 
quired from  both  parents,  which  enable  it  to  take  up  from  its 
environment  the  atoms  for  which  it  has  affinities,  and  which 
develop  it  into  the  morula  form  B.  If  while  in  this  form,  qui- 
escent through  repletion,  it  be  impregnated  or  it  assimilate 
additionally  C,  the  ciliated  still  higher  differentiated  cell,  the 
planula  stage  of  ontogenesis  would  result.  A  many  celled 
mouthless  larva  would  be  the  product  through  B  dividing  into 
A,  which  forms  B  cells,  some  of  which  still  further  develop 
into  C.  Whether  this  passes  direct  to  the  gastrula  stage  D, 
by  imagination,  or  the  gamogenetic  union  results  from  C  and 
D  in  D,  matters  nothing.  At  this  stage  we  can  halt  and  re- 
view our  ground,  and  consider  Darwin's  gemmule  idea  to  have 
arisen  from  the  necessity  for  compactness  of  formation,  for  no 
such  stages  as  subsequently  follow  the  gastrula,  or  for  that 
matter  precede  it,  have  been  discovered  in  higher  metazoa. 

Why  does  ontogenesis  copy  phylogenesis?  is  the  question. 
We  have  seen  that  the  amoeba  may  develop  directly  agamo- 
genetically,  through  acquiring  molecular  possibilities  from  its 
environment. 

An  amcebiform  white  blood  corpuscle  can  also  thus  develop. 
Where  its  chemical  affinities  are  adjusted  to  make  the  first 
step  toward  differentiation  possible,  the  next  step  becomes 
also  possible;  and,  as  chemical  union  constitutes  the  main 
cause  of  development  in  the  amceba,  through  selecting  mate- 
rials in  its  environment,  the  materials  so  selected  will  exist  in 
the  organism,  and  may  be  selected  therefrom  by  the  amcebi- 
form  cell  as  readily  as  from  the  ancestral  environment — even 
better,  for  the  bodily  environment  of  the  amcebiform  corpuscle 
differs  from  that  of  its  ancestor,  and  the  former  has  undergone 
differentiation  through  this  difference,  the  most  noticeable 
being  in  its  sluggish  motions,  probably  due  to  its  repletion, 


54  CLEVENGER — Physiology  and  Psychology. 

which  in  turn  has  developed  a  less  easily  pleased  appetite 
(molecular  affinities  changed  from  that  of  the  amceba,  through 
molecular  constitution  differing  slightly  from  it  by  development). 

This  difference  is  one  of  the  causes  of  ontogenesis  not  copy- 
ing phylogenesis  in  every  particular.  In  passing  to  the  Ab 
stage  (the  potential  morula)  it  is  sufficient  if  the  corpuscle  ac- 
quire ectosarcal  differentiation  tendency,  which  under  proper 
circumstances  might  develop  dynamically.  This,  and  the  en- 
suing step,  could  be  abbreviated  by  the  ingestion  of  a  ciliated 
or  even  an  embryonal  ciliated  cell,  or  by  its  acquiring  the  po- 
tentials of  what  would  develop  a  ciliated  cell,  were  fission  to 
take  place.  All  this  might  occur  and  yet  under  the  micro- 
scope the  amcebiform  cell  would  not  apparently  differ  from  its 
fellows.  We  know  that  these  potencies  exist  in  the  bee  ovum ; 
the  larva  from  which  can  be  developed  into  a  higher  than  the 
neuter  form  through  change  of  food. 

The'potential  gastrula  stage  is  easily  seen  as  a  mere  condition, 
inevitably  ensuing  upon  the  progress  of  molecular  events. 
And  precisely  and  for  the  same  reason  that  ontogeny  abbre- 
viates microscopic  phylogenetic  processes,  so  may  microscopic 
processes  be  abbreviated.  To  make  this  clear,  the  free  animals, 
A,  B,  C,  D,  may  develop  by  gamogenesis  or  by  agamogencsis, 
or  directly  through  effect  of  the  enviroment.  A  may  develop  into 
D.  But,  beyond  this,  differentiation  sets  a  bar  to  this  progress. 
Through  the  operation  of  this  law  low  organisms  may  reproduce 
lost  members,  but  those  highly  differentiated  are  not  repro- 
ducible. 

The  matter  of  sexual  relativity  of  cells  by  differentiation,  as 
well  as  the  hypothesis  that  an  amoeboid  corpuscle  had  in  the 
initial  stages  eaten  a  ciliated  cell,  is  well  illustrated  by  the  fact 
that  the  spermatozoon  is  a  ciliated  cell  and  the  ovum  has  amoe- 
boid likenesses. 


CLEVENGER — Physiology  and  Psychology.  5  5 

The  male  cell  has  taken  the  step  of  differentiation  toward 
combining  the  amoeboid  with  the  potential  planula  by  assum- 
ing the  form  of  a  single  ciliated  cell.  The  abbreviation  or  stage 
of  arrest  being  in  maintaining  the  amoeboid  monocellular 
structure  with  the  cilium  which  belongs  to  the  multicellular 
planula.  The  relative  female  possesses  this  cilium  in  potential, 
or  in  the  locked  up  power  to  develop  it  when  the  proper  time 
comes. 

Ova,  as  we  see  them,  resemble  each  other  morphologically, 
but  not  chemically.  Protoplasm  may  be  the  same,  but  every 
egg  differs  from  every  other  egg  in  possessing  potentials  which 
may  be  in  isomerism,  but  have  not  been  proven,  thus  far,  not 
to  reside  in  the  protoplasm  having  plus  chemical  possibilities, 
differing  not  only  through  isomeric  arrangement  of  molecules, 
but  in  the  intimate  chemical  composition  of  the  ovum  itself. 
The  food  yolks,  when  they  exist,  differ,  and  in  these  there  are 
snored  up,  ready  for  use,  the  molecules  to  be  adopted  by  the 
developing  embryo  in  the  phylogenetic  order  of  their  acqui- 
sition by  the  parent.  One  chemical  combination  being  made, 
and  structure  resulting  from  it,  another  chemical  combination 
is  inevitable,  and  the  structure  must  be  modified  in  accordance 
with  this  very  simple  law.  The  apparent  complexity  of  the 
process  gives  way  when  we  study  the  lower  life  processes.  To 
the  human  mind,  one  and  one  making  two  are  simple  enough, 
but  multiplication,  division  and  subtraction  of  other  numbers 
always  was,  and  always  will  be,  abstract  processes ;  even  after 
the  principles  upon  which  they  depend  are  clearly  understood. 
The  disentanglement  of  simultaneously  acting  multitudinous 
forces  into  their  fundamentals,  does  not  impart  the  ability  to 
predict  everything  that  will  occur  at  separate  instants.  The 
mind  is  only  capable  of  entertaining  one  thought  at  a  time, 
and  while  following  a  thread  cannot  duly  consider  all  the  other 


56  CLEVENGER — Physiology  aud  Psychology. 

threads  in  nature.  So  the  intellect  contents  itself  with  ejacu- 
lating :  Wonderful !  Inscrutable !  Incomprehensible !  The  in- 
tegration of  the  complex,  as  we  see  it,  follows  from  our  seeing 
results  only,  and  being  compelled  to  reason  out  causes. 

The  ontological  copying  of  the  ancestral  development  is  too 
evident  to  mention  in  such  processes  as  segmentation,  invagina- 
tion,  etc. 

The  atomic  falling  into  place  may  be  likened  to  grains  of 
sand  and  other  substances  with  different  facets,  under  the  opera- 
tion of  gravity,  or  other  force,  building  up  identically  two  mor- 
phological structures  where  the  conditions  are  precisely  the 
same  in  both  cases.  But,  as  there  is  a  difference  between  the 
environment  of  the  amoeba  and  that  of  the  amoeboid  corpus- 
cle, that  difference  will  operate  to  modify  the  structure,  and 
we  know  that  natural  selection,  phylogenetically,  modifies  the 
shape,  and  that  ontogenetic  forces  are  at  work  to  do  the  same. 
These  forces  being  in  the  environment  of  the  amoeboid  cor- 
puscle and  its  offspring,  constitute  natural  selection,  as  do  the 
phylogenetic  forces. 

The  adjustment  to  the  environment  is  such  upon  both  causes 
and  effects  as  to  compel  the  modifications  of  both  the  repro- 
duced and  the  reproducing  organisms.  A  process  such  as 
reproduction  being  an  inevitable  consequence  of  growth,  as 
soon  as  it  begins  will  modify  the  parent  processes,  and  these 
will  react  to  modify  the  product,  and  both  together  will  estab- 
lish, not  only  lines  of  least  resistance  for  their  mutual  work- 
ings, but  by  the  law  of  development  will,  whenever  necessary, 
develop  secondary  adjuvant  processes  from  the  environment, 
whenever  a  means  can  be  seized  upon  which  facilitates  the 
process.  For  example,  the  embryo  in  the  amniotic  fluid  is 
under  conditions  simulating  those  of  its  piscine  ancestry,  and 
the  fluid  presence  is  encouraged  because  it  is  adapted  to  the 


CLEVENGER — Physiology  and  Psychology.  57 

ontological  copying  of  the  phylogenetic  method  of  tissue 
making;  but  how  does  the  amnion  arise  which  retains  the 
fluid?  The  origin  and  development  of  the  amnion,  allantois 
and  placenta  can  be  generally  accounted  for  as  structures 
which  ontogeny  developed  out  of  its  environment  to  facilitate 
gestation.  The  cause  of  such  development  of  subsidiary  ap- 
paratus being  in  the  gradual  improving  tendency  of  adapting 
means  to  ends  through  natural  selection.  The  chorionic  villi, 
for  instance,  which  answers  one  purpose,  are  thrown  out  gen- 
erally as  are  the  cilia  of  the  planula,  and  like  those  cilia,  which 
serve  another  purpose,  wherever  a  use  for  them  happens,  there 
villi  and  cilia,  both  serving  the  same  ultimate  purpose,  nutrition, 
develop,  or  are  perpetuated,  and,  where  no  use  is  found,  there  both 
villi  and  cilia  disappear.  This  is  precisely  what  we  know  does 
occur.  That  these  subsidiary  apparatuses  should  be  deciduous 
is  not  to  be  wondered  at,  when,  after  birth,  there  can  be  no  use 
for  them.  If  there  were,  they  would  be  perpetuated,  and 
where,  through  favorable  circumstances  in  the  environment, 
there  exists  that  tendency,  then  this  gives  rise  to  a  form  of 
monstrosity. 

At  birth  the  balance  is  struck  to  obliterate  purely  ontogene- 
tic  apparatus,  such  as  the  allantois,  fcetal  vessels,  etc.,  by  atrophy, 
through  non  use,  or  conversion  into  some  other  useful  organ. 

Extending  this  evident  principle  from  the  embryo  backward, 
it  is  understood  that  development  of  a  developmental  process 
occurs  in  all  its  stages.  So  that : 

Phylogenetic  stages  will  be  abbreviated  ontologically ; 

A  subsequently  acquired  phylogenetic  structure  may,  through 
its  importance,  arise  first; 

Ontogenetic  organs  and  peculiarities  of  development  will 
arise  which  have  no  analogues  in  phylogeny. 

And  the  entire  developmental  methods  of  ontogenesis  will, 


58  CLEVENGER — Physiology  and  Psychology. 

perforce,  so  adapt  means  to  ends  as  to  make  short  cuts,  and 
this  can  and  does  progress  to  such  an  extent  through  oblitera- 
tion of  unnecessary  means,  and  the  adoption  of  new  accessory 
means,  until  the  most  bewildering  differences  of  methods  arise 
by  which  ontogenesis  may  copy  phylogenesis  more  or  less 
faithfully,  and  the  means  of  attaining  the  end  are  through 
simplification,  radically  changed  from  the  phylogenetic. 

This  may  be  likened  to  the  means  by  which  the  modern  me- 
chanic would  set  to  work  to  construct  a  steam  engine.  The 
original  form,  and  many  of  the  evolutionary  steps  of  the  en- 
gine, are  essentially  adhered  to,  but  the  mechanic  has  devel- 
oped his  methods  of  putting  together  his  better  engine  and 
omits  those  parts  which  are  of  no  use,  or  wrhich  were  of  use 
formerly  but  are  not  now,  and  often  builds  an  important  part 
of  the  mechanism  in  advance  of  the  subsidiary  apparatus,  even 
though  the  latter  belonged  to  the  older  and  the  former  to  the 
newer  machine.  Then  the  scaffolding,  which  represents  the 
foetal  appendages,  is,  being  useless,  removed,  and  though  all  the 
evolutionary  methods  have  not  been  resorted  to,  the  more  per- 
fect machine  is  elaborated  and  is  all  the  better  for  the  omission 
of  unnecessary  stages.  But  all  the  useless  stages  are  not 
omitted  in  embryology,  as  is  evident  in  our  retention  of  the 
aural,  plantaris  and  psoas-parvus  muscles.  The  latter,  of  use 
only  in  quadrupeds,  is  present,  according  to  M.  Thiele,  in  one 
out  of  twenty  human  subjects. 


CLEVENGER — Physiology  and  Psychology.  59 


CHAPTER    V. 

DEVELOPMENT. 

It  has  often  occurred  to  me  that  eventually,  with  the  brushing 
away  of  teleological  cobwebs  and  the  introduction  of  physical 
and  mathematical  methods  into  physiology,  there  will  arise  a 
possibility  of  computing  the  lengths  of  the  ages,  in  years,  re- 
quired to  evolve  special  forms,  through  knowing  the  rates  of 
development  and  involution  of  organs,  and  the  conditions  under 
which  changes  occur. 

For  example:  Ancient  Greek  statuary  represented  feeble 
development  of  the  gastrocnemii  and  soleus  with  thoracic  sizes 
upon  which  the  rectus  abdominis  pull  had  not  acted  very  long. 
This,  with  multitudes  of  other  facts,  will  afford  approximate, 
which  may  be  developed  into  exact,  means  for  calculating  the 
length  of  time,  under  given  circumstances,  required  to  develop 
organs  and  organisms.  And  accessory  aid  could  be  rendered 
by  geology  and  archaeology,  with  other  sciences. 

Taking  up  the  genitalia,  the  law  of  differentiation  of  the 
general  excretory  into  oviducts  and  urinary  passages,  which 
empty  into  the  common  cloaca  of  monotremes,  was  followed 
by  the  development  of  a  male  intromittent  organ  through  im- 
pact induration  of  male  ani,  and  the  growth  of  a  sperm  canal 
and  final  complete  external  genitalia.  The  application  of  which 
to  the  complementary  organs  sufficed  to  develop  the  lower 
canal  for  ovulation  into  separate  parts  for  parturition,  etc.,  from 
the  cloaca,  which  now  became  anal. 

As  to  the  so-called  polar  forces,  which  trouble  the  monicists 
to  account  for,  in  the  matter  of  limb  development  we  know 


60  CLEVENGER — Physiology  and  Psychology. 

that  an  organ  not  used  will  atrophy.  We  often  find,  among 
invertebrates,  limbs  attached  to  each  somite,  but  with  a  special 
tendency  to  develop  those  most  used  and  to  a  retrograde  met- 
amorphosis of  those  least  used,  as  in  lobster  development  of 
forceps  and  telson,  and  diminution,  or  at  least  failure,  to  de- 
velop the  intermediate  swimmerets.  This  "  fore  and  aft  "  ten- 
dency of  effort  certainly  differentiated  the  head  end  through 
progression  in  one  direction,  causing  differences  in  environ- 
ment contact,  as  between  head  and  tail.  The  natural  selection 
tendency  in  invertebrata  to  abort  useless  organs,  ontogenesis 
would  develop;  and,  inasmuch  as  a  four-legged  stool  is  even 
better  than  one  with  many  more  legs,  as  allowing  better  center 
of  gravity  adaptation,  the  dipnoi  dfbpped  all  the  extra  fin  ac- 
cessories of  the  fish,  as  the  batrachian  dropped  its  tail;  the 
four  appendages  developed  into  organs  of  locomotion,  and,  as 
might  be  expected  where,  as  in  the  kangaroo  or  other  power- 
ful tailed  animals,  the  three-legged  stool  simile  served  better 
than  the  four-legged,  then  the  extra  legs  are  in  the  way  for 
locomotory  purposes  and  diminish  to  such  an  extent  that  it  is 
doubtful  if  the  kangaroo  should  be  called  quadrupedal. 

The  laws  which  developed  the  polar  members  are  those 
which  indurated  the  tissue  of  the  moving  primitive  animals  by 
impact.  Where  impact  occurred  oftenest,  there  development 
would  occur  through  natural  selection,  with  the  secondary 
elevation  of  more  useful  members  and  extinction  of  the  use- 
less. 

While  the  teleologist  can  see  only  pessimistic  consequences 
from  the  operation  of  such  a  law  in  nature,  to  my  mind  the 
release  from  the  governance  through  absence  of  all  law  in  the 
fanciful  capriciousness  of  a  primum  mobile  which  has  no  analogy 
in  nature,  allows  the  monicist — even  the  pantheistic  kind  of 
monicist — to  derive  optimistic  deductions  from  the  operation 


CLEVENGER — Physiology  and  Psychology.  61 

of  his  laws.  No  matter  how  the  necessity  for  what  develops 
into  a  beneficial  act  or  organ  may  have  accidentally  arisen,  as 
in  the  case  just  cited,  continuance  of  the  working  of  that  law 
in  the  adjustment  of  means  to  ends,  continuance  of  effort  tend- 
ing to  benefit  either  the  organism  as  an  individual  or  society, 
inevitably  will  result  in  the  triumph  of  that  which  is  good  for 
the  animal,  family,  tribe,  nation  and  entire  animate  earth  over 
that  which  is  injurious.  As  the  world  grows  older  it  grows 
better,  from  the  civilized  standpoint  (a  proviso  which  does  away 
with  the  necessity  of  explaining  what  is  meant  by  "better"). 
Superstition,  ignorance  and  crime  gradually  fade  away  in  the 
advance  of  knowledge  of  the  inviolable  laws  which  govern 
the  universe,  and  the  egoistic  realization  that  direct  and 
indirect  advantages  flow  from  decency  and  uprightness  di- 
rectly cause  actions  to  be  adjusted  in  accordance  with  such 
knowledge. 

We  have  in  the  Pseudonematon  nervosum  of  Hubrecht  the 
best  representation  of  the  simplest  quantitative  plexiform  de- 
velopment of  the  nervous  system.  The  hydra  may  show  the 
beginning  in  its  neuro-muscular  cell,  and  I  ascribe  the  failure 
by  others  to  verify  Kleinenberg's  discovery  to  the  fact  that  in 
a  form  initiating  a  differentiation,  many  of  the  species  are  likely 
not  to  possess  the  new  structure,  even  most  of  them. 

This  ectodermally  excreted  compound  of  phosphorus  with 
ordinary  organic  hydro-carbonaceous  materials  brought  about 
a  new  experience  for  the  cell  union.  Whenever  this  compound 
was  disturbed  by  motions  it  exploded,  providing  oxygen  had 
been  previously  furnished  to  it.  However  faint  this  explosion 
may  have  been,  it  became  a  matter  to  be  reckoned  upon  in  the 
cell  environment.  Any  increase  of  heat  in  the  medium  in  which 
the  colony  of  cells  lived  caused  the  nerve  substance  to  act 
more  energetically;  the  "  kick  "  of  the  molecule  was  accelerated. 


62  CLEVENGER — Physiology  and  Psychology. 

This  is  true,  within  limits,  of  all  chemical  combinations,  and 
no  less  in  animal  tissue. 

Light  had  an  effect  upon  it  similar  to  that  induced  by  heat ; 
it  was  feebly  subjected  to  actinic  influences.  Electricity  would 
cause  it  to  act  more  energetically  than  any  other  force,  but  this 
influence  was  only  feebly  present  in  the  environment,  and  seldom 
encountered  in  the  way  of  shocks.  All  animal  protoplasm  is 
affected  by  this  force ;  the  amoeba  will  be  paralyzed  into  the 
quiescent  globular  form  when  it  is  directed  through  it.  Me- 
chanical motions  within  restricted  limits  caused  it  to  act  ener- 
getically, provided  such  molar  motion  induced  molecular 
changes  in  the  cell  contents.  Any  such  latter  motion  would 
affect  the  primitive  nerve  substance. 

It  follows  that  with  this  state  of  things,  at  first  doubtless 
a'nnoying,  a  readjustment  must  occur  in  the  colony  on  the  basis 
of  a  new  mode  of  life  working.  The  cells  then  were  shocked 
by  the  new  tissue,  but  such  forms  as  could  not  get  rid  of  it 
through  agglutination  to  the  ectoderm,  became  reconciled  to 
it,  through  the  reactions  it  caused  being  arranged  against,  in 
its  affecting  adjacent  cell  tissue  toward  obtuseness  to  it.  The 
highly  developed  neurilemma  encystment  is  of  the  same  nature 
as  that  which  covers  foreign  substances  in  the  body,  and  is  a 
conserving  operation  due  to  reaction  of  two  differently  acting 
substances  upon  each  other.  The  intercellular  distribution  of 
these  nerve  granules  would  now  exert  no  effect  upon  the  cells  • 
but  whenever  by  occasional  exposure  of  the  granules  to  an 
influence  which  would  start  the  explosion  it  was  discovered 
that,  instead  of  having  to  wait  for  motions  to  be  transferred 
from  cell  to  cell  before  the  entire  organism  could  be  affected 
by  motory  causes,  this  new  tissue  conveyed  the  needed 
stimulus  promptly  to  a  distant  cell  in  a  very  simple  way.  The 
next  step  was  to  develop  an  arrangement  of  these  granules  in 


CLEVENGER — Physiology  and  Psychology.  63 

rows,  which  we  see  are  at  first  rather  indefinite,  crossing  and 
recrossing  each  other  confusingly.  This  arrangement,  how- 
ever, is  in  obedience  to  the  law  which,  by  final  extension,  ar- 
ranges the  entire  fully  developed  nervous  system  in  all  animals 
—the  law  of  least  resistances.  The  granules  would,  from 
being  diffused,  be  arranged,  by  the  motions  of  the  low  animal, 
in  some  kinds  of  lines,  even  though  badly  defined  ones;  the 
animal  must  now  adjust  his  motions  to  accommodate  these 
rapid  transfers  of  stimuli  from  one  cell  to  another.  The  quick 
conveyance  of  the  impressions  caused  the  cells  to  act  energet- 
ically, and,  in  rapid  succession,  simultaneously;  but  not  always 
sanely,  not  always  with  reference  to  an  object. 

Such  forms  as  were  overwhelmed  by  this  to  such  an  extent 
as  to  interfere  with  food  procuration,  and  hence  furtherance  of 
life,  would  be  killed  off.  If,  by  a  certain  fortuitous  arrange- 
ment, such  as  could  be  effected  by  the  animal  motions,  the 
granules  fell  into  lines  which  would  influence  the  cells  in  such 
a  way  as  to  assist  locomotion  (and,  it  is  easy  to  conceive  that 
almost  any  arrangement  would  cause  it  to  move  in  some  way), 
then  the  facilities  for  travel  which  such  cell  organisms,  such 
as  worms,  would  thus  possess,  would  enable  that  form  to  mul- 
tiply more  rapidly  and  to  escape  trouble  into  which  less  for- 
tunate forms  would  fall. 

The  longitudinal  fibers  of  a  worm  being  pulled  together, 
contracted,  the  circular  fibers  would  be  distended,  which  would 
favor  the  inrush  of  nutrient  material,  one  of  which  is  oxy- 
gen ;  this  exciting  the  muscle  substances  to  contraction,  would 
force  the  longitudinal  to  relaxation  and  allow  it  to  go  through, 
the  same  process.  But  the  absurdity  of  a  springy  worm  like 
this  would  cause  nature  never  to  have  invented  it  without  in-' 
troducing  other  influences  to  prevent  perpetual  motion  or  estab- 
lishment of  equilibrum  with  no  motion  at  all.  These  other 


64  CLEVENGER — Physiology  and  Psychology. 

influences  are  the  ones  operative  in  all  cell  movements,  with 
the  addition  of  the  nerve  apparatus  to  convey  the  stimulus 
to  distant  cells  or  to  all  of  them.  How  could  such  a  nervous 
system  act  to  regulate  these  motions,  simple  as  they  are,  to- 
ward subserving  respectable  locomotory  purposes  ? 

The  primitive  influence  of  external  forces  to  excite  these 
motions  has  not  been  lost,  but  there  are  many  internally  oper- 
ating forces  at  work  to  change  the  resultant  force,  and  the 
worm  has  an  internal  environment  acting  on  its  cells.  When 
this  resultant  is  strong  enough,  through  composition  of  forces, 
to  affect  any  part  of  the  body  more  than  it  does  any  other  part, 
then  mass  motion  of  the  colony  must  radiate  from  that  part. 
This  part,  for  the  time,  dominates  the  rest.  Hunger  being  the 
most  potent,  locomotion  will  develop  in  the  direction  of  hun- 
ger appeasing  motions.  The  part  which  is  most  affected,  the 
intestinal  tract,  and  that  portion  of  it  most  in  need  of  food, 
becomes,  for  the  time  being,  the  center  of  stimuli  production. 
This  influence  is  telegraphed  to  the  other  cells  through  the 
nervous  system,  and  various  motions  in  these  cells  are  thus 
excited. 

Least  resistant  directions  influence  the  motions,  and,  were 
one  point  always  the  exciter,  the  springy  motion  would  con- 
tinue till  exhaustion  overtook  the  animal.  But  the  radiating 
point  for  excitement  must  vary,  and  with  this  there  will  be 
halts,  differences  of  direction,  sinuous  motions  produced, 
which,  with  exhaustion  or  satiety,  for  the  time  being,  cease ;  to 
be  renewed  as  soon  as  a  new  stimulus  arises,  whether  it  be 
hunger  or  some  other  feeling.  Differentiation  decides  from 
which  cells  and  under  what  circumstances  locomotory  in- 
fluences shall  radiate.  Development  of  the  function  proceeds 
with  development  of  adjustment  to  this  change,  and  finally 
differences  in  stimuli  susceptibilities  will  arise  between  the 


CLEVENGER — Physiology  and  Psychology.  65 

cells.  One  set  will  be  affected  under  conditions  which  will  not 
affect  others.  Association  now  steps  in  to  determine  which 
periphery  will  be  linked  to  a  central  method  of  action,  or 
which  condition  existing  in  the  same  periphery  will  affect  the 
center.  The  initial  start  will  be  made  by  exertion  of  such 
muscles  as  are  relaxed,  but  action  is  only  possible  in  such 
muscle  cells  as  are  supplied  with  oxygen,  and  where  this  had 
a  tendency  to  accumulate,  greater  action  would  develop  facili- 
ties for  its  accumulation  there.  The  blood,  no  matter  how 
poorly  developed,  would,  so  long  as  it  carried  oxygen,  be 
brought  to  such  places  in  excess  of  others,  and  with  the  de- 
velopment of  oxygen  carriers,  as  haemoglobin,  a  circulation 
would  result.  The  general  cell  need  of  oxygen  establishes 
an  uniform  method  of  circulation  The  hunger  stimulus 
passes  in  the  line  of  least  resistance;  a  muscle,  the  one  most 
often  first  used,  wherever  that  may  be  located  (usually  in  the 
head  or  tail),  contracts  ;  secondary  causes  radiate  another  in- 
fluence to  contract  other  muscles,  and  where  the  sum  of  the 
influences  are  met  by  opposing  influences,  such  as  might  arise 
externally  or  through  internal  exhaustion,  then  changes  in  the 
nerve  and  muscle  currents  must  ensue,  varying  between  great 
activity  to  quiescence. 

When  the  resultant  diffused  stimulus  arises  to  a  pitch  nec- 
essary to  produce  one  muscle  contraction,  if  this  be  frequent, 
lines  of  least  resistance  will  be  built  up  between  stimulating 
point  and  stimulated  muscle.  Such  influences  as  most  habit- 
ually follow  the  first  will  also  build  up  lines,  and  the  second 
effect  will  follow  the  second  cause  as  the  first  effect  does  the 
first  cause,  and  this  mode  of  motion,  by  development,  will  tend 
to  cohere  and  differentiate  other  modes.  But  the  natural  mode 
of  action  may  be  altered  temporarily  by  operation  of  other 
causes.  These,  too,  if  frequent  enough,  are  adjusted  to  and 

5 


66  CLEVENGER — Physiology  and  Psychology. 

the  number  of  motions  possible  become  limited  only  by  the 
number  of  combinations  of  muscle  contraction  possible. 

In  the  fish  motions  the  compound  curve  may  be  resolved 
into  two  simple  ones.  In  each  of  these  one  set  of  muscles  has 
been  stimulated  to  contraction  through  resultant  energy  acting 
in  it.  The  continuance  of  the  stimulus  would  be  meaningless 
if  it  did  not  find  another,  fresher,  muscle  to  act  upon,  and  the 
opposite  side  finding  this,  the  two  motions  are  made;  four  are 
as  easily  made  and  a  general  adjustment  ensues  to  make  these 
motions  instinctive,  but  alterable  through  second  and  third 
causes. 

A  single  irritation  produces  in  a  muscle,  though  the  nerve,  a 
single  "clonic"  contraction.  The  muscle  cells  develop  a 
tendency,  as  the  conditions  become  more  favorable,  to  respond 
longer  to  a  given  impression.  This  is  shown  in  some  low 
muscles,  requiring  thirty  irritations  per  second  to  fuse  the 
impressions  into  a  tonic  contraction,  and  in  the  development 
of  the  ability  in  some  muscles  to  remain  tetanized  with 
only  ten  stimulations  per  second.  Helmholz  calculates  nine- 
teen and  one  half  as  the  average  "voluntary"  muscle  beat 
tone. 

A  single  impulse  preceding  only  a  single  contraction,  an- 
other impulse  must  follow  the  first  quickly,  or  the  muscle  will 
relax.  It  is  easier  to  send  this  impulse  in  a  different  direction, 
to  a  different  muscle,  one  that  is  under  conditions  favorable  to 
its  being  contracted,  and  the  next  impulse  will  either  be  sent 
to  the  same  or  another  muscle  erratically  through  diffusion,  or 
definitely  through  definite  channel  facilities  having  been  organ- 
ized. When  the  adjustment  is  such  as  to  build  up  channels 
into  inevitable  modes  of  working  as  regards  initial  impulse, 
inevitable  sequences  follow,  and  these  are  taken  hold  of  and 
develop.  One  motion  made,  the  next  is  inevitable,  and  the 


CLEVENGER — Physiology  and  Psychology.  67 

greater  this  development  the  more  instinctively  is  the  motion 
made. 

The  nervous  system  adapts  itself  to  the  instituted  order  of 
things  as  does  the  skeleton  and  other  structures.  The  stage 
prior  to  full  adaptation  of  the  skeleton  is  well  shown  in  Cope's 
fossil  batrachia,*  where  the  vertebrae  merely  held  out  promises 
of  what  vertebrae  should  be. 

Up  to  this  point  we  have  considered  muscles  as  not  being 
separated  from  the  sensitive  molecularly-irritable  protoplasm. 
The  two  properties  of  contraction  and  irritability  developing 
in  the  same  cell  do  not  afford  full  scope  for  differential  motion. 
The  first  chemical  motions  made  by  the  irritable  primordial 
cell  must  be  shared  in  the  same  cell  by  a  motion  which  is  sim- 
ilar, but  grosser,  in  its  results.  That  is,  the  irritability  consists 
in  greater  molecular  mobility,  a  quick  response  to  stimuli. 

Differentiation  of  these  properties  will  separate  off  ganglionic 
gray  areas  from  muscle  areas,  but  it  must  be  remembered  that 
I  do  not  follow  the  traditional  method  of  calling  nerve  cells 
exalted  sensory  organs.  The  irritability  (facile  molecular  trans- 
fer of  force)  develops  in  these  separated  off  protoplasmic  cells, 
and  in  obedience  to  the  law  of  development,  the  cell  wall  being 
an  impediment  to  prompt  transfer  of  molecular  energy  waves, 
is  aborted,  and  the  basis  sensitive  substance  fuses,  with  here 
and  there  evidences  of  maintenance  of  the  limitary  cellular 
ectoderm  and  the  retention  of  the  cell  existence  and  shape  in 
isolated  areas,  to  be  mentioned  further  on. 

I  want  no  mistake  as  to  my  meaning  here,  and  hence  will 
deal  in  concrete  examples  :  The  neuroglia  of  the  spinal  cord 
and  brain  consists  originally  of  a  gelatinous  protoplasmic  sub- 
stance in  which  but  few  if  any  cells  of  any  kind  are  visible,  the 
ganglionic  substance  has  run  together  like  so  much  jelly.  This 

*  American  Naturalist,  1883. 


68  CLEVENGER — Physiology  and  Psychology. 

is  a  developed  condition.  When,  as  in  this  instance,  it  was 
better  that  no  cell  walls  interposed  between  ganglionic  areas 
proliferation  would  proceed  so  rapidly  as  to  abort  the  cell  wall, 
and  not  until  a  later  type  of  organization  set  in,  when  there 
came  stability  of  area  irritation,  do  we  find  cells  with  walls  in 
this  substance. 

Differentiation  does  not  extinguish  original  attributes  in  cells. 
Every  cell  must  eat,  but  where  the  elaboration  of  food  is  car- 
ried on  by  a  cell  f9r  the  benefit  of  the  other  cells,  accidentally 
altruistic  function  through  an  egoistic  process,  that  enteric  or 
glandular  cell  must  preserve  a  due  regard  to  maintaining  some 
of  its  primitive  protoplasmic  attributes  in  other  directions  than 
eating.  If  it  do  not,  then  fatty  degeneration  occurs  and  the 
fat  cell  results  which  may  serve  as  food  for  other  cells  in  time 
of  dearth.  This  primitive  irritability  may,  as  above  stated,  de- 
velop into  isolated  cells ;  and  differentiation  may  occur  to  various 
extents.  Such  irritable  isolated  cells  are  always  peripheral  end 
organ  cells,  and  by  seizing  upon  accidental  materials  in  their 
environment  may  exalt  their  irritabilities  as  the  visual  purple 
or  rhodopsin  chemical  substance  adds  to  the  optic  function. 

The  aggregation  of  masses  of  these  cells  and  their  fusion, 
with  loss  of  cell  envelopes,  constitute  the  rudimentary  spinal 
cord  of  the  amphioxus.  The  scattered  nuclei,  more  evident  in 
the  marsipobranchial  cord  than  in  the  pharyngobranchial,  are 
evidences  of  the  cellular  origin  of  the  neuroglia,  but  the  quan- 
titative increase  of  the  substance  holds  in  check  the  other  cell 
characteristics  as  membranes  and  nuclei,  and,  in  fact,  prolifera- 
tion from  the  few  original  cells  of  this  irritable  substance  would 
constitute  the  ontogenetic  short-cut  toward  accomplishing  the 
formation. 

It  is  evident,  even  in  the  spinal  cord  of  man,  that  segmental 
areas  were  the  first  results  of  separation.  There  are  intervals 


CLEVENGER — Physiology  and  Psychology. 


in  the  cord  corresponding  somewhat  to  vertebral  levels,  where 
cells  are  alternately  many,  and  then  in  other  levels  few.  The 
regularity  of  this  points  to  segmental  fusion. 

Figures  n,  12  and  13  represent  the  stages  by  which  at  first 

irritable  cells  caused  direct 
stimulation  of  muscle  cells. 
The  separation  of  the  two 
forms  of  matter  and  their 

FIG.  ii.  FIG.  12.  FIG.  13.    communication     through 

plexiform  nerve  fibers.  Lastly,  by  arrangements  of  these 
fibers  in  lines  of  least  resistance  the  direct  stimulation  of 
muscle  is  obtained  through  them,  from  the  neuroglia. 

Fig.  14  represents  the  plexiform  fibers  which  convey  in  an 
indifferent  manner  irritations  to  the  neu- 
roglia. Fig.  15  the  definition  of  the 
sensory  nerves. 

Could  we   always   depend  upon   onto- 
genetic  findings    as   setting   forth  phylo- 
Fic.14.  FIG.  15.    genetic  development,  Fig.  16  would  illus- 

trate a  step  by  which  this  develoment  occurred,  and  Fig.  17 
the  next  step,  18  and  19  the  others. 


FIG.  16. 


FIG.  17. 


FIG.  1 8. 


FIG.  19. 


But  we  know  that  from  the  plexus  fibers  both  systems  of 
nerves  arose,  and  ontogenesis  often  inverts  the  order  of  tissue 
and  organ  genesis,  as  in  the  archinephritic  duct  appearing 
before  the  primitive  kidney  arises. 


CLEVENGER — Physiology  and  Psychology. 


Fig.  20  shows  the  neuroglia  segments  related  by  the  plexi- 
form  fibers,  and  this  explains  an  embryological  feature  other- 
wise inexplicable,  thus  stated  by  Balfour:*  "  The  whole  of 


FIG.  20. 

the  nerves  in  question"  (spinal  nerves)  "arise  as  outgrowths 
of  a  median  ridge  of  cells,  which  makes  its  appearance  in  the 
dorsal  side  of  the  spinal  cord.  This  ridge  has  been  called  by 

Marshall  the  'neural  crest'  At 
each  point  where  a  pair  of  nerves 
will  be  formed,  two  pear-shaped 
outgrowths  project  from  it,  one  on 
each  side,  and  apply  themselves 
closely  to  the  walls  of  the  spinal 
cord.  These  outgrowths  are  the 
rudiments  of  the  posterior  nerves. 
While  still  remaining  attached  to 
FlG-  2I-  the  dorsal  summit  of  the  neural 

Vertical    Longitudinal   section   CQrd  they  y/   to    &   considerable 

through  part   of  the  trunk   cf  a 
young   Scyllium    embryo.     Com, 

Commissure  uniting  the  dorsal  "The  attachment  to  the  dorsal 
ends  of  the  posterior  nerve  roots ;  summit  is  not  permanent  But 
prt  ganglia  of  posterior  roots;  before  describing  the  further  fate 
ar,  anterior  roots;  sf,  segmental  r  . ,  ... 

,  ,    ,  of  the  nerve  rudiments  it  is  neces- 

tubes;    sd,  segmental   duct;    ge, 

epithelium  lining  the  body  cavity  sary  to  say  a  few  words  as  to  the 
in  the  region  of  the  future  ger-  neural  crest  At  the  period  when 
minal  ridge.  From  Balfour's  Em-  the  nerves  have  begun  to  shift 

their  attachment  to  the  spinal  cord 

there  makes  its  appearance,  in  elasmobranchii,  a  longi- 
tudinal commissure,  connecting  the  dorsal  ends  of  all  the 

*  Comp.  Embryology,  vol.  ii,  p.  369,  et  seq. 


CLEVENGER — Physiology  and  Psychology.  7 1 

spinal  nerves,  as  well  as  those  of  the  vagus  and  glosso- 
pharyngeal  nerves.  This  commissure  has  as  yet  only  been 
found  in  a  complete  form  in  elasmobranchii,  but  it  is,  never- 
theless, to  be  regarded  as  a  very  important  morphological 
structure. 

"  It  is  probable,  though  the  point  has  not  yet  been  made  out, 
that  this  commissure  is  derived  from  the  neural  crest,  which 
appears  therefore  to  separate  into  two  cords,  one  connected 
with  each  set  of  dorsal  roots." 

He  concludes  that  the  commissure  gradually  atrophies  and 
ultimately  vanishes. 

This  I  regard  as  the  embryological  evidence  of  the  pre- 
existence  of  the  plexiform  fibers  and  the  derivation  of  the 
spinal  nerves  from  them. 

If  we  can  accept  the  illustration  and  description  of  the  am- 
phioxus  longitudinal  nerves  in  Owen*  as  exact,  the  pneumo- 
gastric  and  lateral  column  of  the  cord  formation  would  be  easily 


FIG.  22. 

Spinal  Nerves  of  Scyllium  in  longitudinal  section,  to  show  th'e  Commissure 
connecting  them.  A,  Section  through  a  series  of  nerves.  JB,  Highly  magnified 
view  of  the  dorsal  part  of  a  single  nerve,  and  of  the  Commissure  connected  with 
it.  Com,  Commissure;  sp,  g,  ganglion  of  posterior  root;  ar,  anterior  root. 
From  Balfour. 

explained.     The  sympathetic  nervous  system  rises  above  mar- 
sipobranchii.     In  this  form  the  pneumogastric  is  distributed 

*  Comp.  Anat.  and  Physiol.  of  Vertebr.,  vol.  i,  p.  270 


CLEVENGER — Physiology  and  Psychology. 


to  the  intestine.  Hunger  being  the  primitive  desire,  and  oper- 
ating mainly  with  and  against  other  forces,  and  tending  to  ren- 
der accessory  to  itself  all  materials  and  forces 
that  natural  selection  had  thrown  in  its  way,  it 
seems  reasonable  that  impressions  from  the 
intestines  should  dominate  the  motions  through 
the  early  plexiform  system.  It  also  seems 
reasonable  that  as  the  head  of  the  animal  dif- 
c-  ferentiated  through  variability  of  the  environ- 
^  ment  meeting  that  end  more  than  the  other 
|  parts,  that  hunger  can  only  control  the  loco- 
motion through  being  associated  with  the 
|  impressions  received  elsewhere  and  gaining 
1  control  of  locomotion.  The  great  number  of 
S  impressions  received  at  the  head  end  must  act 
to  interfere  with  the  hunger  motions,  in  which 

o 

I  case  the  animal  would  starve,  or  it  must  act 

a  to  assist  them.     Only  such  forms  would  sur- 

«  vive  as  allowed  the  head  impressions  to  cohere 

g  with  the  intestinal  for  the  benefit  of  the  animal. 

£  This  should  be  made  clear:      Grant  a   nidi- 

ca 

|     mentary  olfactory  sense  to  the  marsipobran- 


«     chial  nasal  pit.     Certain  molecular  rotations  of 

3     food  substances  caused  a  sensation  of  smell  in 

the  animal.     If  no  notice  were  taken  of  this, 

fO 

N  no  association  of  it  with  the  hunger  sense 
would  occur.  If,  as  is  likely,  the  smell  and 
the  hunger  attraction  occurred  at  the  same 
time,  at  first  faintly,  finally,  through  persist- 
ence, very  strongly,  came  the  chemical, 
attraction,  hunger,  to  cohere  with  the  chem- 
ical .  molecular  rotation,  constituting  odor. 


CLEVENGER — Physiology  and  Psychology.  73 

Association  was  inevitable.  Where  the  association  was 
strongest  the  facility  for  food  acquisition  would  be  devel- 
oped. Natural  selection  would  pass  this  new  experience, 
smell,  into  an  adjuvant  of  the  hunger  attraction.  The 
adjustment  of  the  cells  would  be  such,  when  pushed  against 
certain  odorous  substances  continually  by  the  hunger  at- 
traction, to  make  odorous  rotations  coincide  in  their  manner 
of  affecting  the  motions  with  the  hunger  molecular  mo- 
tions. This  coincidence  is  association.  The  same  power 
is  at  work  to  adapt  means  to  ends  in  the  highest  organ- 
ism, and  may  be  coarsely  paralleled  by  the  behavior  of  many 
inorganic  substances,  which  adjust  themselves  to  new  second- 
ary conditions  to  such  an  extent  as  to  often  make  the  secondary 
conditions  the  mainly  operative.  When  odorous  food  sub- 
stances act  upon  a  terminal  sensitive  cell  (ciliated)  in  such  a 
way  as  to  start  an  impulse  along  the  olfactory  nerve  to  the 
neuroglia  cells,  and  this  segment  of  neuroglia  formation  is  ex- 
cited into  corresponding  activity,  the  activity  of  that  segment 
occurring  simultaneously  with  the  intestinal  hunger  sensation, 
no  matter  where  the  latter  radiated  its  influence  in  the  pro- 
duction of  motions,  the  two  impressions  would  mechanically 
build  up  least  resistant  lines  between  them,  as  may  be  seen  by 
forming  the  sand  figures  of  Chladni  by  drawing  violin  bows 
across  opposite  edges  of  the  plate  of  glass  upon  which  the 
sand  is  strewn.  A  resultant  series  of  molecular  methods  of 
vibrating  would  inevitably  be  constructed  in  that  head  end 
segment  where  the  olfactory  and  hunger  impressions  met,  to 
excite  the  motor  nerves. 

Association,  then,  consists  in  a  mean  molecular  or  vibratile 
motion.  Under  the  microscope  some  of  the  results  of  this 
molecular  disturbance  might  be  apparent  if  conditions  admit- 
ted of  such  inspection.  A  mean  between  the  waves  sent  from 


74  CLEVENGER — Physiology  and  Psychology. 

two  places  to  a  common  center.  These  vibrations  may  not 
differ  in  kind  from  all  others  to  which  the  neuroglia  is  suscep- 
tible, except  in  intensity;  the  location,  the  seat  of  association, 
being  in  the  higher  segment  close  to  the  olfactory  tract. 

This  favors  the  idea  afforded  us  by  ontogeny,  that  the  sen- 
sory cerebro-spinal  nerves  arise  before  the  motor. 

At  this  juncture  the  general  spinal  motor  nerves  are  per- 
forming their  force  conveyance  office  to  the  muscles  to  move 
the  body,  in  obedience  to  the  hunger  instinct  and  reflexes;  but 
with  the  addition  of  so  important  an  aid  as  the  smelling  fac- 
ulty the  food  is  more  directly  obtained,  and  vermicular  motions 
of  the  intestinal  tract  are  more  promptly  excited  through  food 
contact.  The  two  classes  of  motions,  anterior  neuroglia  seg- 
mental,  and  intestinal  vermicular,  acting  simultaneously,  or 
almost  simultaneously,  or  successively,  will  build  up  associa- 
tion motor  tracts  between  segment  and  gut,  not  for  the  pur- 
pose of  eating,  but  because  the  eating  is  associated  with  that 
segment  irritation.  This  becomes  an  advantage.  The  irritation 
of  the  olfactory  segment  neuroglia  excites  prompt  motions  of 
the  intestines  in  the  simplest  and  most  direct  manner. 

The  motor  branches  of  the  pneumogastric  are  built  up  out 
of  such  subsequently  exuded  particles  of  nerve  substance  as 
the  enteric  cells  may  pass  into  the  body  channels  and  intercel- 
lular spaces.  Instead  of  passing  to  build  up  other  nerves,  pre- 
viously formed,  they  now  arrange  themselves  in  a  new  set 
of  nerve  fibrils  through  operation  of  the  law  of  least  re- 
sistances. 

All  those  organs  concerned  in  the  elaboration  of  food  for  the 
body,  such  as  the  respiratory,  hepatic  and  general  glandular, 
have  the  hunger  sense  developed  in  excess  of  other  senses. 
It  is  for  this  reason  that  the  sensory  pneumogastric  fibrils  pass 
to  these  organs  as  well  as  to  the  intestines,  and  because  cellu- 


CLEVENGER — Physiology  and  Psychology.  75 

lar  motions  of  the  same  nature  occur  in  these  organs,  though 
differentiated,  as  those  in  the  intestines,  motor  tracts  of  the 
same  associating  nerve  unite  the  head  segments  with  these 
viscera  as  with  the  intestines. 

Let  us  here  dispose  of  a  little  physiological  superstition : 
It  was  considered  a  great  mystery  why  an  impulse  over  one 
nerve  should  result  in  saliva  secretion,  and  one  over  another  in 
lachrymal  production,  etc.  This  may  be  understood  by  liken- 
ing the  nervous  system  to  a  pole.  If  the  pole  be  used  to  dis- 
turb or  stimulate  a  cuttle  fish,  in  the  usual  order  of  things  you 
may  have  ink  as  the  result.  If  the  same  pole,  or  another  like 
it,  be  used  to  stimulate  a  skunk,  you  will  not  get  ink  as  a  re- 
sult. The  secretory  faculty  lies  in  the  cell  of  the  non-nervous 
structure,  and  has  relations  to  the  nervous  system  the  irasci- 
ble animals  mentioned  have  to  the  sticks  and  stones  which  strike 
them. 

All  these  organs  act  through  motions  induced  in  their  cells 
by  direct  influences  upon  these  cells,  and  until  organic  develop- 
ment has  reached  a  stage  such  as  we  find  in  teliost  fishes,  an 
association  system  of  sympathetic  fibers  could  not  exist,  be- 
cause there  was  not  sufficient  stability  to  the  organs.  With 
their  full  development  the  same  causes  of  simultaneous,  con- 
secutive or  associated  action,  effective  in  cerebro-spinal  nerve 
formation,  would  now  begin  in  the  viscera.  A  plexiform  sys- 
tem of  fibrils  would  creep  over  and  enmesh  the  organs,  and  in 
the  establishment  of  nutrient  reflexes  build  up  connections 
with  the  cerebro-spinal  nerves.  Every  motion,  whether  molec- 
ular or  molar,  which  induced  waste  necessitates  repair.  The 
motions  which  accompany  all  life  processes  draw  blood  to  the 
points  of  activity,  and  in  proportion  to  the  preponderance  in 
this  respect  of  one  part  of  the  body  over  the  other,  so 
will  the  circulatory  channels  enlarge  toward  it,  and  the 


76  CLEVENGER — Physiology  and  Psychology. 

reflex  systems  necessary  to  hasten  action  in  this  direction  will 
appear. 

Instead  of  building  the  sympathetic  association  system  be- 
tween the  blood  vessel  and  point  simultaneously  active  through 
each  muscular  motion,  making  a  direct  draught  upon  blood  ves- 
sels, and  thus  associating  motions.  Instead  of  running  the 
sympathetic  fibres  between  muscle  and  vessel,  the  conserving 
energy  of  nature  would  find  a  more  direct  means.  In  fact, 
were  such  an  arrangement  to  occur,  the  muscle  ends  would 
atrophy  as  soon  as  the  cerebro-spinal  nerve  connection  with 
the  sympathetic  had  been  effected.  The  motion  in  cerebro- 
spinal  nerve  fibers  caused  the  muscle  motion,  which  in  turn 
caused  the  blood  to  flow  toward  the  muscle,  or  rather  facili- 
tated it.  Association  of  the  muscle  motion  with  the  blood 
vessel  motion  is  transferred  through  the  sympathetic  fibers 
(which  facilitate,  or,  in  a  certain  sense,  cause  the  vascular  ac- 
tion) uniting  with  the  cerebro-spinal  nerves,  which  prompt  the 
muscle  motion,  thus  making  a  short  cut  for  the  nutritive  pro- 
cess, by  which  time  is  saved,  energy  conserved,  and  through 
which  differentiation  has  proceeded  and  will  proceed.  As 
every  vascular  pulsation  has  reverberating  secondary  pulsa- 
tions all  over  the  body,  the  molecular  nerve  motion  passes  over 
the  vessels  to  the  smallest  arteries,  and  as  every  spinal  nerve 
action  produces  wide-spread  general  vascular  pulsations,  pro- 
portioned directly  to  size  of  nerve  and  importance  of  function, 
a  commissural  line  of  bands  creep  along  the  anterior  vertebral 
bodies  and  unite  all  the  spinal  nerves  and  the  cerebral  to  the 
spheno-palatine  ganglion  through  commissures  to  the  vidian 
end  of  the  commissure. 

The  great  splanchnic  nerve  is  the  intermediary  between  vis- 
ceral motions  and  those  locomotory  and  other  hunger  appeas- 
ing motions  which  operate  together 


CLEVENGER — Physiology  and  Psychology.  77 

Lack  of  oxygen,  excess  of  carbonic  acid,  or  other  causes, 
produce  vermicular  motions  of  the  intestines,  which  are  mainly 
through  contractions  of  the  circular  fibers  passing  downwards. 
Of  course  apncea  is  induced  by  too  much  oxygen  and  the  mo- 
tions stop  through  surfeit.  These  motions  are  wholly  inde- 
pendent of  the  cerebro-spinal  system,  though  the  pneumogas- 
tric  cognizes  them  and  may  incite  them  to  greater  activity. 
Stimulation  of  the  vagus  tract  increases  the  motion,  while 
stimulation  of  the  splanchnic,  which  is  of  the  nature  of  the 
fibers  passing  over  the  viscera,  can  only  interfere  with  the  low 
grade  motions  of  these  nerves  and  paralyze  the  involuntary 
muscle  cells,  through  tetanizing  them,  as  the  amoeba  assumes 
the  globular  quiescent  form  when  electrified.  Surgical  shock 
is  of  this  nature. 

The  splanchnic  is,  as  are  other  special  sympathetic  bands, 
built  up  through  persistence  of  force  and  least  resistance  to 
accommodate  supply  of  blood  to  general  motor  waste  of  tissue. 
The  vascular  condition  of  large  areas  is  kept  in  tone  through 
sympathetic  ganglia  areas  and  where  a  distant  vascular  tonus 
is  changed  arterial  dilatation,  for  example,  is  caused  by  need  of 
repair  in  adjacent  muscular  action.  The  associated  recurrence 
builds  up  more  direct  fasciculi  to  cause  simultaneous  compen- 
satory action.  The  general  bodily  loss  of  arterial  tonus  would, 
in  distributing  equilibrium  through  the  general  sympathetic 
and  more  directly  through  the  splanchnic,  effect  its  com- 
pensation more  or  less  rapidly;  but  where  conveyance  to  so 
important  an  organ  as  the  brain  necessitates  much  prompter 
regulation,  the  cervical,  carotid  and  cardiac  sympathetic  dis- 
tribute the  tonus,  as  is  shown  when  by  injury  to  the  cervical 
fibers  or  ganglion  the  head  is  suffused  with  blood.  The  lep- 
tocardiac  pulsations  show  that  the  muscles  of  the  heart  are 
independent  of  the  nervous  system  for  motility.  The  sympa- 


78  CLEVENGER — Physiology  and  Psychology. 

thetic  attempts  to  distribute  the  pulsations  along  the  vessels  in 
an  equilibrating  way,  but  through  its  cords  and  gangliar  con- 
nections it  acquaints  the  cerebro-spinal  nerves  with  the  status 
of  the  cardiac  and  vessel  tone,  and  the  complicated  inhibitory 
and  acceleratory  effects  are  developed  by  association. 

The  vesical  and  uterine  sympathetic  nerves  coming  from  the 
same  plexus  as  the  colic,  indicate  that  the  general  excretory 
and  generative  excretory  functions  are  in  many  respects  still 
identical. 

Rythmical  uterine  contractions  are  of  this  nature,  and  react 
upon  the  lumbar  cord  for  acceleratory  stimulation.  Emotional 
causes  may  stop  the  spinal  action.  Micturition  is  an  equiva- 
lent process  and  subject  to  the  same  rules  as  other  visceral  move- 
ments. 

The  motor  spinal  nerve  elements  are  noticeably  larger  in 
diameter  than  those  of  the  corresponding  sensory  nerves,  and 
this  law  of  sizes  holds  good  for  the  axis  cylinders  and  asso- 
ciated nerve  cells  in  many  areas. 

With  the  conveyance  inward  to  the  cord  of  a  multitude  of 
vibrations  representing  or  evoking  sensation,  the  seat  of  which 
is  in  the  cerebro-spinal  axis,  the  tendency  of  adjustment  is  such 
as  to  resist  many  impressions  received  in  the  interests  of  the 
organism.  It  would  not  answer  to  have  every  impact  and  cell 
disturbance  felt  so  keenly  as  to  cause  reflex  action.  It  is  in 
higher  life  the  unexpected  impression  which  does  this.  In 
lower  forms,  as  in  the  sea-squirt,  the  vast  majority  of  impres- 
sions act  to  project  its  water.  The  brainless  frog  moves  its 
limb  when  touched,  but  remains  indifferent  to  other  impres- 
sions which  do  not  suffice  to  stimulate  the  simple  or  complex 
reflexes  adjusted  through  past  experience. 

The  evolution  of  this  adjustment  is  best  followed  up  from 
the  amoeba. 


CLEVENGER — Physiology  and  Psychology.  79 

This  representative  of  the  living  cell  has  its  environment 
adaptation  through  reaction  of  external  causes  upon  internal 
structure  to  the  end  that  hunger  appeasing  locomotion  may 
not  be  interfered  with.  The  compromise  is  made  with  the  sur- 
roundings. At  first,  any  change  from  the  normal  would  cause 
a  motion  which  is  equivalent,  for  our  purpose,  to  a  sensation, 
and  identical  with  it.  The  recurrence  of  these  changes  must 
be  adjusted  to  by  molecular  reintegration.  If  the  changes  act 
in  the  food-procuring  direction,  the  molecular  arrangement  is 
integrated  with  the  hunger  arrangement  and  associated  action 
occurs.  The  operation  of  the  change,  then,  is  to  excite  and 
promote  hunger  motions;  but  if  the  changes  oppose  food- 
procuring,  the  animal  must  die  unless  a  compromise  be  made, 
and  it  depends  upon  the  ability  of  the  molecules  to  readjust 
themselves  against  the  change  whether  survival  occurs  or  not. 
In  many  it  does  not — may  be  in  most  of  the  primitive  animals. 
In  some  it  does,  whether  accidentally  or  not,  the  adjustment 
will  be  transmitted  to  the  offspring  and  perpetuated.  This  may 
be  through  induration  to  blunt  reaction,  or  through  softening 
to  disperse  it.  The  protoplasm  may  be  likened  to  a  strong 
attractive  energy  seated  in  a  mobile  mass  of  granules  which, 
however  the  environment  may  operate,  often,  not  always,  in 
time,  thro.ugh  the  resultant  changes  wrought,  enables  the  native 
attractive  ability  to  be  exerted  in  a  modified  way.  Those  less 
modified  are  perpetuated  and  multiply,  but  inevitably  a  re- 
arrangement is  effected  and  new  relations  with  the  outer  world 
are  established.  The  injurious  impression  ceases  to  become  a 
stimulus ;  the  favorable  one  is  taken  advantage  of,  and  contin- 
ues to  excite  reflexes  until  finally  it  unconsciously  does  so ;  the 
molecules  being  adjusted  in  an  instinctive  way  to  oppose  as 
little  resistance  as  possible. 

So  those  impressions  which   cause  quivers  in    the  central 


8o  CLEVENGER — Physiology  and  Psychology. 

neuroglia  always  affect  spinal  motor  nerves  according  to  seg- 
ments excited.  If  a  sensation  does  not  produce  the  quiver 
(cognized  by  higher  animals  as  consciousness),  then  the  sen- 
sory impression  must  have  been  adjusted  against  by  resistance 
arrangement  of  nerve  granules,  or,  in  some  other  way,  some- 
thing is  interposed  to  minimize  or  destroy  the  impression,  as 
one.  Foot  callosities  are  the  grossest  method  of  accomplish- 
ing this,  and  here  inner  to  outer  relations  are  compromised. 

The  same  result  could  be  attained  by  lessening  the  nerve 
fibrils  in  number  or  sizes  of  cross  sections  to  a  part,  or  by 
atrophy  of  sensitive  peripheral  cells.  What  physical  law  is 
there  that  introduces  counterbalancing  agencies  toward  con- 
servation of  living  structures  in  such  instances  ?  With  man, 
injurious  surroundings  excite  attempts  to  escape  from  them  re- 
sembling the  indefinite  movements  made  by  low  grade  animals 
in  their  reflex  movement  to  all  impressions.  Failing  in  this, 
man  makes  the  best  of  the  matter,  and  in  time  may  thrive  un- 
der the  change  through  finding  some  elements  in  it  which  may 
be  turned  to  account.  Disagreeable,  i.  e.,  hunger  intensifying 
impressions, — ultimately  resolvable  into  such, — promote  greater 
cell  activity  if  mass  motion,  which  is  first  evoked,  does  not 
suffice  to  remove  the  cause,  then  the  continued  cause  acting 
upon  large  areas  of  cells  make  extensive  changes,  until  a  suf- 
ficient equilibrating  change  is  effected  somewhere,  and  a  bal- 
ance is  struck.  The  hunger  appeasing  motions  have  now  the 
victory  and  the  obnoxious  impression  has  ceased,  even  though 
the  cause  still  exists.  The  impression  may  be  disposed  of  in 
many  ways :  diffusion  channels  may  distribute  it  over  a  large 
surface  of  sensitive  tissue  by  development,  injurious  impacts 
may  disease  (reintegrate)  nerve  or  other  tissue  destructively, 
so  as  to  resist  the  impression  in  varying  degrees,  or  the  epider- 
mal thickening  through  stimulation  of  cell  growth  may  blunt 


CLEVENGER — Physiology  and  Psychology.  8 1 

the  effect.  In  which  case  the  sensory  strands  tend,  through 
non-use,  to  lessen  their  sizes  and  numbers.  So,  while  there 
are  a  few  causes,  as  in  the  optic  and  auditory  sense  differentia- 
tion, which  tend  to  develop  sensory  nerve  fibrils  in  certain  areas 
with  conservative  natural  causes,  keeping  them  and  their  asso- 
ciated apparatus  within  useful  development  bounds,  there  are 
many  causes  incessantly  at  work  to  make  such  development 
undesirable,  and  retrograde  changes  incessantly  operate  to  in- 
crease resistance  of  sensory  nerve  fibrils  by  lessening  their 
axis  cylinder  cross  section,  and  in  other  ways,  resulting  in  evo- 
lution of  useful  and  destruction  of  useless  or  injurious  sense 
channels. 

But  as  the  adjustment  of  the  inner  to  the  outer  workings  is 
through  interposing  changes  between  the  cerebro-spinal  axis 
and  the  periphery,  motions  of  that  axis  once  set  up  radiate 
over  motor  nerves  which  are  not  subject  to  the  injurious  in- 
fluence of  an  often  inimical  world.  The  inner  tissues  are  on 
adjusted  friendly  terms  with  each  other.  They  have  shaken 
down  to  smooth  working  through  egoistic  necessity,  which 
always,  when  intelligence  progresses,  finds  that  mutual  assist- 
ance is  beneficial  to  self  in  the  highest  degree.  The  friction- 
less  workings  of  the  motor  apparatus  have  been  acquired 
through  ages  of  inherited  adjustments,  and  hence  motor  nerve 
fibrils  are  adapted  to  their  work,  and  seldom  being  retrograded, 
maintain  a  relatively  larger  size  than  the  sensory  nerve  fibrils, 
for  the  reason  that  where  in  the  latter  tissue  resistance  is  a  de- 
sideratum, the  minimization  of  resistance  through  increased 
size  of  fiber  is  equally  desirable  in  the  former. 

Rythmic  motions  of  organs,  such  as  blood  vessels,  and  the 
establishment  of  cyclical  phenomena,  such  as  menstruation, 
seem  to  me  to  have  arisen  thus  :  With  the  constant  presence 
of  oxygen  in  the  air  and  water,  the  entrance  of  oxygen  causes 

6 


82  CLEVENGER — Physiology  and  Psychology. 

the  amoeba  to  move.  The  molecular  rotations  unavoidable  in 
chemical  interchange  would  expand  the  albuminous  tissue  and 
the  water  presence  in  the  mass  admits  of  this  rotation.  The 
disengagement  of  carbonic  acid  which  follows,  is  another 
source  of  motion.  These  two  motions,  unlike  the  general 
assimilatory,  would  act  toward  increasing  the  bulk  of  the  ani- 
mal, if  both  gases  were  retained.  The  carbonic  acid  being 
excrementitious  must  be  thrown  off.  It  exhales  from  the 
ectosarc  or  accumulates  in  the  vacuoles  with  the  water  there. 
The  oxygen  expansion  acts  with  the  food  expansion  to  finally 
propel  the  vacuole  contents  outward.  The  animal  would 
burst  otherwise.  The  passage  outward  of  the  vacuole  is  not 
always  seen.  It  may,  by  the  growth  pressure,  be  broken  up 
into  minute  particles  which  pass  between  the  granules  and 
through  the  ectosarc.  This  matter  must  be  projected  outward 
or  the  animal  would  grow  indefinitely  or  burst.  The  latter 
event  would  liberate  the  gas  if  it  came  to  that  pass,  and  the 
exhalent  process  is  like  a  disruption.  Whatever  may  be  said 
of  the  other  pabulum,  oxygen  is  generally  present,  and  CO2 
exhalation  must  occur  after  the  oxygen  inspiration.  The  one 
act  follows  the  other,  for  one  being  the  cause  of  the  other  the 
act  of  expiration  can  but  follow  that  of  inspiration.  This  con- 
stant action  produces  the  rythm  observable  in  the  amoebic 
vacuole  contractions,  and  where  that  rythm  is  absent  it  is 
through  interference  to  which  all  animals  are  subjected,  and 
irregular  pulsations  or  respirations  follow. 

In  the  intestines  this  downward  peristaltic  motion  is  due  to 
oxygen  and  tactile  impressions,  and  in  the  highly  developed 
lung  the  oxygen  and  CO2  exchange  cause  the  same  rythmic 
respirations  as  in  the  amoeba.  In  the  arteries  and  heart  the 
waves  of  pulsation  occur  as  the  haemoglobin  of  the  corpuscles 
yields  up  a  nutrient  modicum  to  each  cell  as  they  pass.  These 


CLEVENGER — Physiology  and  Psychology.  83 

cell  movements  stimulate  reverberatory  molecular  motions  in 
the  sympathetic,  and  these  fibers  convey  their  motions  feebly, 
stimulating  the  muscle  cells  ahead  to  contraction  and  the 
tonus  of  all  the  vessels  are  thus  brought  about. 

If,  through  lines  of  least  resistance  a  special  strand  of  the 
sympathetic  relates  distant  parts,  then  the  stimulus  will  skip  a 
large  area  of  intermediate  cells  and  act  upon  the  distant  part 
direct. 

The  splanchnic  thus  telegraphs  the  tonus  condition  from 
the  intestines  and  stomach  to  the  general  voluntary  muscular 
system  and  entire  body  through  the  commissures  on  the  ven- 
tral part  of  the  vertebral  column.  The  cervical  and  carotid 
strands  relate  the  vessels  of  the  brain  with  lower  levels  of  ves- 
sels, etc.  When  the  ovum  has  reached  a  certain  stage  of  ma- 
turity it  provokes  profound  changes  which  must  be  accounted 
for.  Simultaneous  development  of  several  ova  are  likely  to 
occur  where  the  conditions  are  the  same  in  the  body,  and  such 
full  development  appears  to  require  a  lunar  month. 

At  the  expiration  of  this  time  the  excretory  desire  of  the 
cell  provokes  expulsive  motions,  the  growth  of  the  ova  pro- 
duces an  irritation  on  adjacent  parts  which  advances  to  an  ex- 
treme. Associated  cell  action  use  up  more  oxygen  than 
usual,  and  a  process  equivalent  to  a  local  inflammation  occurs. 
More  blood  is  sent  where  there  is  increased  activity,  and 
through  associated  habitual  action  the  engorgement  becomes 
useful  if  the  cell  be  impregnated  and  thus  possess  the  requi- 
site chemical  affinities  to  exert  other  effects  upon  the  uterus. 
If  the  ovum  is  not  impregnated,  it  has  not  changed  from  its 
early  excrementitious  nature  in  lower  animals  and  is  cast  out 
with  the  released  menstrual  blood,  which  at  this  stage  is  also 
useless,  setting  up  a  physiological  haemorrhage  varying  in 
quantity,  duration,  painfulness  or  regularity  with  different 


84  CLEVENGER — Physiology  and  Psychology. 

females,  showing  that  full  adjustment  has  not  occurred.  In 
fact,  the  inconvenience  and  sickness  thus  produced  upon  nearly 
all  females  show  the  pathological  origin  of  the  function. 

The  development  of  gestation  from  the  oviparous  to  the 
viviparous  is  merely  through  longer  retention  of  the  embryo  in 
the  mother,  and  some  reptiles  and  amphibia  are  known  to  pos- 
sess the  faculty  of  breeding  in  either  way.  The  rule  being  that 
higher  development  is  obtained  through  such  longer  retention, 
and  applied  to  sociological  matters  the  analogy  holds  good. 
Higher  development  is  obtained  for  children  through  fostering 
of  parents  than  where  they  are  turned  loose  to  shift  for  them- 
selves too  soon. 

With  the  mammary  appearance,  an  associated  action  of  the 
uterus  and  ovaries  is  made.  In  marsupialia  the  excitement  of 
the  mammary  glands  by  the  young  follows  their  birth.  At  the 
monotreme  origin  of  this  mode  of  nourishment  but  feeble 
effect  was  produced  by  the  attachment  to  the  breasts  ;  subse- 
quently, where  blood  was  drawn,  epithelial  induration  was 
caused,  which  formed  the  teats,  and  the  epithelial  cells  thus  pro- 
duced were,  with  their  increase,  eaten  by  the  offspring.  The 
blood  increased  the  quantity  of  these  cells  to  the  parts  as  the 
parts  were  drawn  upon,  and  the  reparative  process  is  converted 
into  a  maternal  act  of  nourishment.  These  cells,  instead  of 
passing  to  the  dermis,  were  sucked  through  canaliculi,  and  in 
the  immature  condition  for  reparation  passed  with  the  serum 
drawn  from  the  blood  of  the  mother  to  the  young  animal. 
The  vessels  had  adjusted  against  blood,  as  such,  being  drawn, 
finally  passing  out  with  the  serum  only  cells  in  a  state  of  fatty 
degeneration,  constituting  the  milk  globules  which,  through 
adaptation,  become  the  easiest  yielded  up  and  the  most  nutri- 
tious to  the  offspring. 

With  this  d-jvclcnrr.ent  came  the  ontological  preparation  for 


CLEVENGER — Physiology  and  Psychology.  85 

these  glands,  and  with  the  stages  of  growth  mammae  grew  in 
keeping  with  the  body  of  the  female. 

The  birth  preceding  the  breast  attachment  through  probably 
millions  of  years,  the  blood  vessels  associated  the  two  irrita- 
tions in  sequence,  so  that  when  the  ovaries  were  excited  the 
breasts  would  be  also. 

Ovarian  and  uterine  agitation  and  growth  become  associated 
by  simultaneous  disturbances  with  breast  growth,  and  the 
blood  vessels  thus  simultaneously  acted  upon  form  in  lines  of 
least  resistance  to  carry  on  the  associated  function.  The  sym- 
pathetic nervous  system  along  these  vessels  ending  in  glands  in 
a  double  row  from  fore-leg  to  groin,  originated  just  as  we  de- 
scribed the  simultaneous  occurrence  of  odor  and  food  pressure 
caused  the  production  of  the  pneumogastric.  When  the  ovary 
or  uterus  was  then  irritated,  the  breasts  would  be  stimulated  to 
degrees  of  excitement,  as  odors  produced  the  hunger  motions 
of  the  intestine.  The  converse  in  both  cases  is  slightly  true. 
Irritations  of  the  breast  are  sometimes  felt  in  the  genitalia,  and 
hunger  in  primitive  animals  may  produce  feeble  odor  halluci- 
nations. In  man,  the  olfactory  sense  has  diminished  to  such 
an  extent  as  to  be  of  but  little  use,  and  hence  seldom  aroused 
to  hallucinations. 

Vicarious  menstruation  through  the  nipples  is  thus  accounted 
for  by  an  imperfect  adjustment  of  the  process. 

During  normal  menstruation  the  outflow  checks  the  further 
disturbance  of  the  breast.  During  gestation  the  blood  is  dis- 
tributed between  breast  growth  and  embryonal  nutrition. 

The  hunger  theory  accounts  for  the  female  desire,  but  upon 
what  principle  can  we  base  the  corresponding  male  desire?  In 
amoeba,  monads,  etc.,  the  relative  female  or  germ  cell  eating 
the  relative  male  or  sperm  cell,  on  the  part  of  the  latter  was  a 
somewhat  passive  transaction.  The  hunger  appeasing  of  the 


86  CLEVENGER — Physiology  and  Psychology. 

female  was  followed  by  its  plethoric  quiescence;  and  in  the 
case  of  an  amoeba  which  had  eaten  a  synamceba  segmentation 
would  begin  and  the  amoeba  released  developing  into  either 
form  or  both  forms,  depending  upon  the  degree  of  ectosarcal 
preponderance.  At  this  low  stage  to  eat  or  be  eaten  could 
have  no  such  significance  they  have  in  a  higher  life.  It  was 
a  process  of  overcoming.  The  amoeba,  with  its  low  ectosarcal 
interference,  could  eat  the  synamceba  better  than  the  latter 
could  the  former. 

Sociologically  the  money-grubber  devours  the  services  of 
men  of  brains,  and  the  issue  of  the  business  is  development  of 
faculties  and  facilities  for  mercantile  improvement  both  in  the 
sordid  and  mental  aspects. 

The  adjustment  of  the  relative  male  toward  perpetuation 
involved  his  being  finally  eaten  to  enable  him  to  survive  at  all, 
and  with  the  rapidity  of  his  new  birth  and  fusion  with  the 
female,  it  is  conceivable  that  in  this  fusion  an  indifference  to 
the  process  would  ensue  from  the  chemical  aspects  as  to  which 
ate  the  other,  the  only  question  being  one  of  feasibility.  The 
impediment  to  the  process  would  be  the  ectosarc  degree.  The 
one  which  had  less  of  this  impediment  would  be  the  eater,  and 
the  one  with  more  the  eaten. 

But  as  the  developmental  stages  advanced  and  copulatory 
acts  grew  from  this,  it  is  not  so  clear  how  this  sexual  union 
could  afford  any  gratification  to  the  absolute  male,  save 
through  remembering  that  excretory  necessity  is  transferred 
from  the  organism  to  its  cells  and  the  sperm  cell  increase 
(capable  of  stimulation  through  revivification  of  causes  which 
before  stimulated  it)  is  associated  with  excretory  desire. 
Through  gradual  evolutionary  associated  method  of  excretion, 
from  fusion  of  germ  and  sperm  cell  direct  to  hemaphroditic 
fusion  desire  between  the  products  of  ectodermal  and  endo- 


CLEVENGER — Physiology  and  Psychology.  87 

dermal  cells,  the  gratification  of  the  cells  became  a  mode  of 
gratification  of  the  tissues  and  entire  colony  of  cells.  When 
sexes  developed  into  separate  organisms,  the  cell  desires  which 
had  been  operative  during  millions  of  years  of  evolution  were 
quickened  into  existence  when,  at  first,  accidental  contact  (as 
in  juvenility,  when  the  organism  first  is  astounded  into  a  recog- 
nition of  this,  to  it,  new  experience),  next  through  memory  and 
association,  step  by  step  the  process  has  grown  with  develop- 
ment of  the  genitalia  to  its  present  modes  of  working.  The 
excitement  of  the  entire  body  in  this  act  is  the  recognition  by 
the  organism  cells  of  the  necessity  for  it,  and  the  realization 
of  a  suppressed  desire,  intense  in  proportion  to  its  previous 
deprivation,  less  intense  with  satiety,  precisely  as  precedence 
of  pain  or  pleasure  makes  all  desire  purely  relative. 

The  trout  and  other  teliosts  recognize  the  spawn  through 
this  association  having  been  connected  through  the  optic  sense 
and  the  sperm  ejaculation  is  excited.  This  associability  is 
transferable  to  such  a  degree  as  to  account  for  first  one  sense 
then  another,  may  be  several  senses,  as  olfaction  in  dogs,  the 
optic  in  fishes,  and  auditor}  in  mosquito  male,  and  the  tactile 
in  all,  being  respectively  alternately  and  together  excited.  In 
man,  the  optic,  through  association,  from  savage  to  civilized 
experience  refers  to  a  slightly  exposed  ankle  what  before  was 
only  generated  by  contact  or  a  glimpse  of  other  parts. 

The  interdependence  of  the  tissues  is  such  that  an  abnormal 
condition  arising  in  ont  point  may  set  up  many  changes  in  dis- 
tant parts.  For  instance,  a  change  in  the  assimilative  abilities 
of  an  intestinal  or  glandular  cell  may  chemically  change  what 
it  excretes,  and  by  transfer  alter  the  food  of  remote  and  re- 
moter cells  until  excreted.  Itching,  pruritus,  and  other  ob- 
scurely caused  conditions,  as  urticaria,  which  is  induced  often  by 
eating  shell  fish,  have  these  relationships  of  cause  and  effect. 


88  CLEVENGER — Physiology  and  Psychology. 

Profound  changes  were  entailed  by  the  exchange  of  the  wa- 
tery medium  of  the  Sozura,  or  tailed  amphibia,  occasionally 
resorted  to  by  them,  and  the  advance  to  the  protamnia  stage. 

Not  only  were  the  gills  aborted  by  this  loss  of  the  watery 
environment  in  which  they  were  bathed,  and  the  lung  devel- 
oped, but  the  amniotic  development  became  necessary  and  was 
a  consequence  of  having  left  the  water,  whereby  ontogeny  sub- 
stituted an  accessory  means  of  copying  phylogeny,  and  the 
embryo  was  passed  in  utero  through  the  aquatic  stages  to  the 
pro-reptilian  and  pro-mammalian  stages. 

The  organ  of  tears  originated  at  this  time,  by  the  painful  des- 
sication  of  the  eye  ball  front  exposed  to  light,  rendering  an 
occasional  dip  into  the  water  by  the  amphibian  necessary,  at 
first,  until  adjusted  balance  of  water  distribution  thereabouts 
could  occur. 

The  water  received  by  the  eye-ball  from  the  sea  or  river 
grew  less  necessary  as  the  outpour  from  behind  the  eye  became 
facilitated,  and  the  lachrymal  gland  was  created.  This  was  a 
purely  mechanical  process,  similar  to  the  bibulous  capillary 
attraction  of  blotting  paper  in'  its  distribution  of  water  in  one 
part  to  the  other  parts.  The  dry  cells  of  the  anterior  part  of 
the  globe  drew  upon  the  wet  cells  further  back,  and  as  the  ad- 
justment to  this  draught  enlarged  the  water  capacity  for  the 
rearward  cells,  a  certain  group  developed  into  the  function  of 
furnishing  this  fluid  to  lubricate  and  protect  the  eye,  and  a  con- 
tinuous life  out  of  the  water  was  made  possible. 

The  pain  of  the  light-glare  thus  associated  with  the  tear- 
flow  afforded  an  important  serviceable  associated  habit  for  a 
multitude  of  grief  and  pain  expressions  which  subsequently 
arose.  Previously,  pain  was  otherwise  associated. 

The  dropping  of  the  tail  seems  throughout  to  have  been  a 
promise  of  higher  cerebral  development,  and  where  the  caudal 


CLEVENGER — Physiology  and  Psychology. 


vertebrae  have  persisted  in  any  line,  the  development  of  the 
encephalon  has  been  slow  in  that  line.  The  tail  seems  to  have 
persisted  in  our  phylum  to  the  prosimiae. 

In  most  invertebrates  there  are  no  morphological  distinctions 
of  sensory  and  motor  nerves,  and  as  in 
low  worms  we  have  reason  to  believe  the 
two  functions  are  not  separated,  we  will 
have  to  assume  that  the  muscle  cells  are 
mainly  stimulated  by  transference  of  irri- 
tation from  one  cell  to  the  other;  but 


ii 


13 

*•* 


d    o£ 

Otor 


2j  •=  &    the   ganglia  cells,    which    are    originally 

s«   "**"    ^ 

*  ~  Jg  neurogha,  or,  as  we  may  term  them,  sen- 
£  §  <9  sorv»  are  united  by  a  commissural  cord 
2,-S  £  (Hirudo  medicinalis).  These  ganglia  cor- 
respond with  the  somites,  except  where 
fusion  occurs.  Leuckart  *  counts,  in 
the  leech,  thirty  pairs  of  post-oral  ganglia, 
but  the  seven  posterior  and  the  three  an- 
terior pairs  coalesce.  Nerves  are  given 
J[  off  to  the  pharynx  and  intestines,  and  the 
former  develop  special  ganglia.  The  post- 
oral  commissure  we  may  look  upon  as  a 
sensory  nerve  relating  the  sensory  gang- 
lia; the  filaments  given  off  from  -the 
ganglia  may  be  regarded  as  motor.  All 
impressions  pass  from  the  head  and 
somites  to  cause  a  contractile  wave. 

Directly  upon  the  anterior  segment  are 
placed    simple  eyes,  nerves  from  which 
pass  to  the  supraoesophageal  ganglia. 

The  feebly  appreciated  impressions  are  carried  backward 
*  Huxley's  Invertebrate  Anatomy,  p.  191. 


90  CLEVENGER — Physiology  and  Psychology. 

to,  and  through,  or  by,  the  sensory  ganglia,  thence  ra- 
diating through  motory  nerves  to  somite  groups  of  muscle 
cells. 

In  the  transference  of  stimulation  of  one  cell  to  another,  the 
observed  facts  of  the  nervous  system  afford  simple  explana- 
tions of  their  modes.  The  granular  fibrillae  lie  upon  and 
among  the  cells  in  direct  contact  with  them.  This  is  true  of 
sensory  gangliar  matter  as  well  as  all  glandular  and  muscular 
tissue.  When  the  fibrillae  are  naked,  of  course,  large  areas  of 
cells  are  affected  through  direct  impressions ;  but  when  they 
are  medullated,  isolated,  insulated,  action  carries  the  stimulus 
to  a  distance. 

It  was  very  puzzling  to  histologists  to  see  how  simply  the 
nerve  fibrils  ended,  spread  over  muscles  and  projected  into 
spinal  cord  gray.  It  showed  that  contact  of  the  nerve  fibril 
only  was  required  to  bring  out  the  peculiar  mode  of  action 
of  each  cell  when  excited.  Were  the  hirudinea  sensory  nerves 
connected  directly  with  the  muscles,  then  a  nonsensical  rigor 
would  perpetually  seize  the  animal,  without  definite  end.  The 
interposition  of  the  sensory  cell  set  a  bar  to  this  by  introducing 
switch  points  to  muscle  areas  and  affording  the  muscle  nerves 
a  reliable  and  constant  method  and  source  of  initiating  motion. 
Instead  of  millions  of  different  points  acting  erratically  upon 
muscles  direct,  the  myriad  impressions  were  sent  to  a  few 
ganglia,  and  these  radiated  the  impressions  to  the  muscles,  as 
from  reservoirs,  making  the  motions  definite,  and  imparting 
regularity  where  otherwise  there  would  be  confusion. 

It  is  only  necessary  to  imagine  that  this  jelly-like  neuroglia 
substance  of  the  ganglion  area  quivered,  and  that  this  was  pro- 
duced by  nerve  irritation,  and  in  turn  produced  nerve  irrita- 
tions ending  in  definite  muscular  contractions. 

With  the  fusion  of  ganglia  and  the  constant  passage  of  nerve 


CLEVENGER — Physiology  and  Psychology.  91 

influences  in  a  certain  direction,  from  head  to  tail,  changes  in 
those  structures  must  occur. 

In  the  acrania  but  little  difference  exists  between  cranial  and 
spinal  nerves.  None  of  them  possess  intervertebral  ganglia. 
Free  nuclei  abound  in  the  ganglionic  masses,  and  the  next  step 
is  a  quantitative  development  of  the  cranial  ganglia,  owing  to 
the  greater  frequency  of  impressions  there.  Then  granules 
abound  about  these  nuclei,  interspersed  without  much  order 
in  the  lamprey  cord;  finally,  in  higher  animals,  assuming  fibrillar 
and  clustered  arrangement.  The  nuclei  afford  the  centers  for 
this  clustering,  but  the  direction  in  which  the  neuroglia  quivers 
pass  would  arrange  the  fascicular  rows  and  form  the  columns 
of  the  cord,  becoming  medullated  if  there  were  differences  in 
modes  of  action  of  the  two  tissues,  as  a  resultant  of  the  two 
modes.  Such  new  medullated  fibrils  as  remained  uncovered 
in  the  neuroglia  substance  indicate  modes  allied  to  those  of  the 
matrix  from  whence  they  sprung,  and  their  directions  indicate 
the  tendency  of  the  neuroglia  quivers  to  pass  the  tremors  in 
certain  ways.  Failure  to  establish  thorough  uniformity  of  di- 
rection indicating  the  conflicting  nature  of  the  disturbances 
diffused  through  the  cord.  But  a  resultant  arrangement  will 
be  compromised  upon  and  the  fascicular  picture  of  the  fibrillae 
show  strong  tendencies  toward  arrangement.  Most  persistent 
directions  and  complex  arrangements  show  the  presence  of 
contending  directions. 

From  the  neuroglia  substance  by  proliferation  of  eminently 
sensory  cells,  of  which  the  scattered  nuclei  are  remnants,  and 
the  loss  of  their  cell  walls,  which  was  a  developmental  feature, 
arose  again  a  disposition  to  reform  the  cell  wall,  when  through 
clustering  of  granules  about  a  nucleus  this  was  made  possible. 
The  granule  parturition  of  some  of  these  embryonal  cells  is 


92  CLEVENGER — Physiology  and  Psychology. 

excellently  shown  in  the  researches  of  Schmidt.*  A  cell  be- 
comes surcharged  with  granules,  the  wall  bursts,  and  liberates 
the  granules  which  mingle  with  the  general  fibrillae.  Sensoiy 
cells  of  the  neuroglia  are  seen  in  the  morula  stage,  and  so- 
called  mother  cells  are  seen  to  divide  by  fission,  as  does  the 
amoeba. 

Association  of  impressions,  or  the  simultaneous  action  of  two 
sensations  in  lines  of  least  resistance,  build  up  the  filaments 
which  go  to  form  the  sensory  strands  on  the  posterior  and 
postero-lateral  columns  of  the  cord,  and  simultaneously  acting 
motions  also  build  up  the  strands  of  the  antero-lateral  and 
anterior  columns. 

Every  nerve  cell  contains  granule  contents.  The  shape  of 
the  cell  and  the  direction  of  the  granules  are  determined  by 
the  composition  of  forces.  This  cell  merely  admits  of  definite 
transmission  through  it  of  the  motions  common  to  all  nerve 
fibrillae,  and  owing  to  the  comparative  fixity  of  these  directions 
the  cell  wall  binds  the  fibrillae  in  place  and  affords  it  a  local- 
ization. 

Herbert  Spencer  claims  that  function  precedes  structure,  and 
in  the  evolution  of  mind  from  chemical  affinity  (a  function  of 
matter)  this  is  evident. 

We  have  somewhat  fully  considered  structure,  or  what 
function  has  integrated ;  now  let  us  turn  to  the  effect  of  func- 
tion upon  structure,  and  show  how  the  mind  has  reacted  upon 
the  body  to  build  up  the  brain. 

In  the  amoeba  we  saw  that  chemical  affinity  acting  in  its  pro- 
toplasm constituted  hunger,  which  was  the  primitive  desire, 
and  that  locomotion  was  effected  through  gratification  of  this 
hunger  or  through  the  desire  to  gratify  it. 

*  Journal  of  Nervous  and  Mental  Disease,  July,  1877. 


CLEVENGER — Physiology  and  Psychology.  93 

The  sexual  appetite  was  differentiated  from  the  hunger  ap- 
petite as  soon  as  special  cells  developed  to  carry  on  the  sexual 
ingestion  and  excretion. 

The  tactile  sense  feebly  separated  from  the  hunger  sense  as 
soon  as  cilia  developed,  and  the  locomotory  tactile  as  soon  as 
organs  of  locomotion  were  fully  developed. 

The  remaining  senses  arose  by  differentiation,  but  up  to  the 
time  a  nervous  system  formed,  the  too  independent  action  of 
these  desires  and  functions  must  have  operated  but  feebly  to 
conserve  the  general  good  of  the  organism.  With  the  advent 
of  the  plexiform  nervous  system  no  one  cell  could  suffer  pain 
or  pleasure  without  instant  participation  therein  of  all,  or  most 
of,  the  other  cells.  This  became  an  advantage  comparable  to 
the  linking  together  of  continents  by  electric  cables,  which, 
apprising  distant  parts  of  activities  therein,  attune  the  general 
behavior  accordingly;  and  who  doubts  that,  since  cables  have 
been  laid,  wars  have  been  rendered  less  possible,  and  that  a 
better  international  understanding  has  been  brought  about  ? 

Instead  of  the  worm-cells  warring  with  one  another,  and  an 
impression  reaching  one  part  of  it  long  after  the  possibility  of 
the  organism  to  act  in  accordance  with  the  impression  had 
passed,  now  the  stimulus  was  instantaneous,  and  the  cells  were 
brought  into  close  sympathy  with  each  other,  where  before, 
through  cell  to  cell  influence,  this  sympathy  was  feeble  and 
often  ineffective.  A  new  resultant  from  the  summation  of  in- 
ternal cell-activities  arose,  but  all  must  be  subordinated  to  the 
food-acquiring  ability  which  throughout  all  animal  life  must 
dominate  or  the  animal  perishes.  However  differentiation  may 
have  masked  desire,  the  fundamental  hunger  guides  the  mo- 
tions, and,  having  its  base  in  chemical  affinities,  man  is  at- 
tracted or  repelled,  as  the  animals  are,  from  that  which  is 
pleasureable  or  painful.  The  boor,  generally,  thinks  only  of 


94  CLEVENGER — Physiology  and  Psychology. 

his  food  or  of  some  of  the  lower  offshoots  of  the  appetite  for 
it,  and  in  the  scale  of  intelligence  of  animals  through  to  the 
savage,  barbarian,  and  civilized  man,  our  only  knowledge  of 
the  intelligence  of  others  is  derived  from  witnessing  in  them 
motions  better  and  better  co-ordinated  toward  the  food-acquir- 
ing and  allied  functions,  and  finally  the  development  of  such 
facility  for  food-acquisition  as  to  make  it  hold  an  apparently 
subordinate  place  in  our  reflexes,  with  consequent  leisure  and 
ability  to  develop  and  differentiate  in  directions  which,  though 
based  upon  hunger-appeasing,  apparently,  to  the  unthinking, 
have  no  reference  to  it  whatever.  All  desire  is  based  upon  it, 
and  the  developed  desires  fade  away  in  inverse  order  of  their 
creation  precisely  as  the  fundamental  ability  to  get  food  is  in- 
terfered with.  Whether  starving  from  sickness  or  poverty,  no 
artist  or  scientist  can  think  of  anything  but  his  need,  and  if, 
through  rebellion  among  the  cells  of  the  organism,  or  through 
indifference  of  neighboring  animals,  this  extreme  arises,  the 
result  is  the  same  in  degrading  toward  the  basal  instincts  and 
desires.  Where  a  "  ruling  passion  "  struggles  through  adversi- 
ties to  manifest  itself,  it  must  be  strong  indeed,  and  society 
has  fought  all  innovators  toward  beneficent  development  from 
the  law  of  cell-resistance  to  foreign  materials  until  they  gain  a 
foothold.  Then,  society  and  the  cell  complacently  adjust  to 
the  new  order  of  things  and  plume  themselves  upon  their 
shrewdness  and  ability. 

To  conceive  of  what  the  lower  animals  think,  we  may  resort 
to  the  objective  method  of  inspecting  their  motions  as  they 
grow  more  and  more  intelligent,  in  proportion  as  their  cells 
are  internuncially  related  by  the  nerve-fibers,  and  subjectively 
by  remembering  the  sluggishness  of  our  own  motions  and 
sensations  when  we  "  feel  stupid "  or  are  falling  off  to  or 
awakening  from  sleep.  Objectively  we  thus  judge  of  insanity. 


CLEVENGER — Physiology  and  Psychology.  95 

In  certain  diseases  of  the  nervous  system  the  nerve-fibrils  do 
not  convey  the  sensation,  and  the  brain  receives  the  impres- 
sion slowly  through  the  gray  matter  of  the  cord,  or  until  a 
higher,  unaffected  strand  can  pass  it  upward.  Many  seconds 
elapse  before  a  pin,  stuck  in  the  body,  is  felt.  This  is  a  path- 
ological dissociation,  which  is  extreme  as  regards  sensation  in 
anaesthesia  and  as  regards  motion  in  paralysis. 

If  the  sensory  and  motor  chemical  acts  of  the  amoeba  are 
judged  as  constituting  its  thought,  then  to  think  of  something 
to  eat,  to  feel  the  desire  to  eat,  and  to  move  with  reference  to 
getting  food,  are  one  and  the  same  thing.  When  the  cells  are 
so  separated  as  to  perform  different  offices,  each  thinks  mostly 
of  its  peculiar  function,  which,  with  reference  to  the  associated 
cells,  may  constitute  a  difference ;  but  with  the  cell  itself  the 
fundamental  desire  has  changed  but  little.  Thus  the  cells  de- 
voted to  reproduction,  hunger,  and  they  desire  to  excrete,  and 
in  so  doing  are  related  to  the  organism  as  establishing  a  differ- 
ence of  mode  of  action  from  the  lower  cells. 

The  act  of  the  muscle  cell  is  an  inspiratory  eating  one  when 
it  contracts,  and  so  on  throughout  the  body.  The  seat  of  the 
action  constitutes  the  sensation  difference  and  the  quantitative 
development  of  cells  devoted  to  the  performance  of  a  function 
determine  the  intensity  of  the  feeling.  The  nervous  system 
merely  converts  the  irritation  from  these  seats  into  vibratory 
terms  and  conveys  it  to  the  sensorium  commune,  the  neuroglia, 
which  is  more  responsive  according  to  its  quantitative  develop- 
ment, its  aggregation  into  a  cerebro-spinal  axis,  and  its  being 
furnished  with  association  fibers  to  relate  distinct  parts. 
Hence  mind  is  located  in  every  living  cell  of  the  body,  and  the 
better  nervous  association  of  these  cells  constitute  grades  of' 
intelligence.  Cells  vary  as  animals  do  between  themselves. 
The  most  molecularly  active  cells,  such  as  the  gangliar  basis 


96  CLEVENGER — Physiology  and  Psychology. 

substance,  have  developed  an  irritability  beyond  what  the 
amoeba  possessed  through  differentiation  of  its  molecular  mo- 
bility, that  being  the  activity  which  best  appeases  its  hunger. 

When,  after  rest  and  the  restoration  of  nutrition,  we  feel  well 
and  strong,  every  cell  desires  to  carry  on  its  function  and  excites 
the  body  to  general  activity. 

Such  cells  as  have  developed  the  highest  degree  of  molecular 
activity,  have,  through  this  development,  acquired  an  exalted 
mental  activity,  but  while  thus  the  neuroglia  is  the  seat  of  this 
exaltation,  it  is  one  of  degree  only,  for  every  other  cell  cannot 
be  denied  mentality  as  long  as  chemical  interchanges  go  on  in 
that  cell.  Consciousness  increases  with  the  number  of  cells  prop- 
erly related,  and  with  the  facility  of  tissues  to  undergo  chemical 
metamorphosis.  Mind  develops  with  the  coordination  of 
these  chemical  relations,  a  coordination  which  is  possible  only 
through  phylogenetic  and  ontogenetic  processes.  The  panthe- 
istic applications  of  this  to  all  inorganic  nature  I  have  nothing 
to  do  with  in  this  essay,  and  leave  deductions  of  that  kind  to 
others. 

With  every  impression  received,  every  cell  impressed  is  re- 
adjusted. It  assumes  a  different  shape,  its  molecules  and  gran- 
ules are  differently  arranged,  and  varying  densities  are  instituted 
in  different  parts  of  the  cell,  from  colloidal  conditions  to  states 
of  rigid  immobility,  depending  upon  the  cause  and  the  nature 
of  the  cell  and  its  contents.  With  this,  adjacent  and  remote 
cells  are  affected,  as  no  cause  has  but  one  effect.  Nature  is  full 
of  the  operation  of  this  law.  Given  one  cause,  the  remote  effects 
flowing  from  it  are  inconceivable  in  extent  or  importance. 

The  better  adjustment  of  the  cell  to  its  work  constitutes 
instinct ;  the  hesitancy  in  response  to  the  cause,  through  resist- 
ance to  the  new  arrangement,  may  be  called  thought ;  and 
whenever  the  effect  of  the  first  cause  is  reproduced,  no  matter 


CLEVENGER — Physiology  and  Psychology.  97 

how,  whether  by  direct  repetition  of  the  first  cause,  or  by  asso- 
ciation, or  by  any  extrinsic  influence,  this  repetition  of  the  first 
effect  constitutes  memory. 

Instinct,  reason  (thought),  memory,  are  thus  but  modes  of 
cell  adjustment  and  operation;  and  the  instinct  producing  less 
disturbance  than  the  reason  impression,  so  the  memory  exer- 
cised in  reasoning  is  of  a  more  noticeable  character  than  the 
memory  evoked  in  instinctive  motions,  because  the  instinct  and 
the  instinct  memory  are  facile  workings  of  the  cell,  while 
reason  and  the  reason  or  thought  memory,  are  difficult,  in 
degree,  workings  of  cells,  in  which  or  for  which  adjustment  is 
incomplete  to  the  impression.  As  soon  as  the  adjustment  is 
made  the  reason,  thought,  ceases  and  instinct  begins. 

The  inevitable  consequence  of  this  is  to  hand  mind  in  all  its 
manifestations  of  reason,  instinct,  memory,  etc.,  over  to  the  gen- 
eral body  cells,  with  mind  par  excellence  seated  in  the  cerebro- 
spinal  gray  matter,  which  may  be  called,  though  only  relatively 
so,  the  seat  of  consciousness. 

There  is  then  a  motor  mind  through  the  motor  apparatus 
adjustment  made  up  of  a  motor  instinct,  reason  and  memory. 
The  latter  was  considered  by  Kiissmaul  *  as  a  necessity  from 
conditions  of  aphasia,  such  as  inability  to  pronounce  a  word 
even  though  it  was  in  the  sensory  mind.  He  called  it  "  Beweg- 
ungsbildcr" 

Reviewing  the  processes  of  development  of  the  central 
nervous  system,  its  simplicity  is  wonderful ;  and  Spitzkaf 
affords  us  a  succinct  account  of  the  steps,  which  may  be  sum- 
marized thus : 

Two  axial  gray  ridges  rise  up  on  each  side  of  the  embryo ; 
these  ridges  fuse  to  form  a  tube  around  the  central  ciliated  ep- 
ithelial canal. 

*  Berliner  Klin.  Woch.    1870,  Nos.  37,  38. 
fArchitecture  and  Mechanism  of  the  Human  Brain. 

7 


98  CLEVENGER — Physiology  and  Psychology. 

"  The  first  indication  of  the  cerebral  formation  is  a  pyriform 
enlargement  of  the  anterior  end  of  the  medullary  tube,  which, 
like  the  parent  tube,  is  hollow.  The  walls  of  the  enlargement 
(primitive  cerebral  vescicle)  are  composed  of  the  same  ele- 
ments arranged  in  the  same  radiatory  manner  as  the  walls  of 
the  rest  of  the  medullary  tube.  Through  all  subsequent  mor- 
phological changes,  the  cellular  elements  of  the  brain  hence 
maintain  a  vertical  position  to  the  surface  contour  of  their  re- 
spective locality,  unless  their  position  is  disturbed  by  interrup- 
tory  fibers. 

"  The  primitive  cerebral  vesicle  exhibits  two  constrictions 
which  subdivide  it  into  three  lesser  segments,  each  of  which 
contains  a  more  or  less  round  cavity,  connected  with  the  other 
cavities  of  the  constricted  lamina.  These  vescicles  we  desig- 
nate as  the  (i)  fore  brain,  (prosencephalon) ;  (2)  mid  brain, 
(mesencephalon),  and  (3)  hind  brain  (postencephalon)." 

The  thalamus  and  hemispheres  constitute  a  structural  con- 
tinuity and  rank  with  the  corpus  striatum  as  such. 

"  Water  breathers  constituted  the  ancestry  of  the  vertebrate 
sub-kingdom,  and  it  is  reasonable  to  suppose  that  the  olfactory 
lobe  constitutes  one  of  the  most  ancient  differentiated  seg- 
ments of  the  central  nervous  system.  In  the  myxinoid  fishes 
and  the  lamprey  the  cerebral  hemispheres  themselves  are  mere 
appendages  of  the  olfactory  lobes,  and  hardly  Jialf  their  size" 

Morphological  considerations  are  of  secondary  importance 
in  a  psychological  essay,  but  I  have  never  seen  good  reasons 
for  vacating  the  ground  I  took  in  declaring  the  intervertebral 
ganglia  of  the  spinal  cord  to  be  homologous  with  all  the  tuber- 
cles and  lobes  of  the  brain  and  the  laminae  of  the  cerebellum*. 

The  Gasserian  ganglion  is  indisputably  an  intervertebral. 
The  olfactory  lobe  of  all  animals  (in  man  degenerated  to  a 
tract)  is  an  intervertebral,  the  optic  lobes  of  the  teliost  fishes 
are  homologous  with  the  intervertebral,  and  are  erroneously 

*  Journal  of  Nervous  and  Mental  Disease,  October,  1880.  American  Natur- 
alist, January  and  February,  1881,  and  July,  1881.  Chicago  Medical  Journal 
and  Examiner,  November,  1880. 


CLEVENGER — Physiology  and  Psychology.  99 

called  its  cerebrum ;  the  globular  shape  of  the  cerebellum  lobes, 
even  in  highly  developed  animals,  and  the  passage  from  these 
globules  to  a  laminated  form  in  quadrumana  and  man,  and  the 
fact  that  all  such  ganglia  have  only  sensory  nerves  passing 
through  them,  are  the  main  points.  The  reasons  in  full  and 
extension  to  aborted  lobes,  such  as  the  pineal  gland,  etc.,  are 
given  in  the  papers  mentioned. 

However  subsequent  ontogenetic  fusions  may  picture  the 
intervertebral  and  the  spinal  gray  as  morphological  units, 
Balfour*  distinctly  shows  these  swellings  of  the  posterior  roots 
to  be  developed  in  scyllium,  independently  of  the  medullary 
tube,  and  the  nerve  root,  with  its  anterior  companion,  subse- 
quently join  the  tube. 

In  its  earliest  stages  above  the  lancelet  such  an  interposi- 
tion of  primitive  sensitive  substance  could  operate  in  no  other 
way  than  as  an  etapc  to  blunt  the  incoming  dorsal  sensory  im- 
pressions in  the  interests  of  other  and  cephalic  ganglia. 

The  forward  appearance  of  these  ganglia  are  significant  as 
intermediating  certain  impressions  before  allowing  the  cord  to 
be  affected,  such  cord  impressions  indicating  inevitable  motor 
response. 

The  olfactory  lobe  or  intervertebral  thus  quenched  certain 
useless  sensory  impressions  which,  before,  were  mixed  up  with 
the  pneumogastric  hunger  senses,  and  at  this  stage  higher  dis- 
crimination began. 

The  question  of  vertebral  origin  of  the  cranial  bones  seems 
to  have  been  settled  by  Huxley's  dictum  that  these  latter  arose 
at  the  same  time  with  the  vertebrae,  and  through  partaking  of 
the  segmental  peculiarities  the  cephalic  modifications  render 
them  siti  generis.  So  with  my  intervertebral  homology.  In 

*Comparative  Embryology,  Vol.  II,  p.  371. 


ioo  CLEVENGER — Physiology  and  Psychology. 

the  main,  I  believe  it  to  be  true,  but  in  this  essay  it  does  not 
become  an  essential  beyond  best  accounting  for  developmental 
processes.  It  suffices  to  regard  the  fact  of  secondary  gray 
interposition  upon  sensory  nerves,  no  matter  how  it  arose. 

With  this  suppression  of  certain  vibrations  of  no  immediate 
use  to  the  animal,  a  discrimination  caused  by  physical  processes 
eventually  came  about,  a  determination  through  commissural 
erection  of  association  of  these  hitherto  useless  impressions  into 
useful  ones. 

This  should  be  made  clear : 

I  claim  that  every  impression  reaching  the  spinal  cord  pro- 
duces a  corresponding  muscular  or  glandular  motion  some- 
where, unless  inhibited  by  a  secondary  apparatus,  to  be  regarded 
further  on.  Any  way,  the  motor  apparatus  is  affected. 

Such  as  olfactory  sensations  occurring  simultaneously  with 
the  hunger  sensations  cause  a  tract  between  the  points  of 
reception  of  these  sensations  in  the  gray  to  be  affected,  and 
subsequently  linear  arrangement  of  primitive  pneumogastric 
fibrils. 

Many  mistakes  must  occur  and  the  excitement  be  produced 
when  there  is  no  food  present  and  the  animal  is  "  fooled." 

But  with  the  tendency  toward  differentiation  of  impacts  these 
especial  vibrations,  which  are  unerringly  associated  with  foocl 
presence  in  the  olfactory,  continue  their  former  effect,  while 
the  vibrations  which  were  mistaken  for  food  odors  affecting  the 
ganglion  cells  (neuroglia)  in  a  different  manner,  however 
slightly,  became  dissociated  by  the  most  natural  means. 
Thus  we  see  in  intervertebral  ganglia  fibrils  passing  through 
the  ganglion  and  others  ending  in  it. 

These  ganglia  feel  as  do  other  cell  aggregates,  particularly 
such  sensory  cells,  but  as  they  are  comparatively  isolated  what 
they  feel  does  not  affect  the  organism  until  with  commissural 


C  LEV ENGER — Physiology  and  Psychology.  I  o  I 

union  such  ganglia  as  the  cephalic  unite  their  modes  of  motion 
with  others. 

Transverse  commissures  are  attracted  by  simultaneous  ex- 
citement in  kind  of  bilaterally  placed  gray  masses. 

Longitudinal  commissures  are  built  up  by  simultaneous  or 
successive  excitement  in  kind  or  totally  different  excitement 
occurring  in  different  levels  of  the  body. 

When  the  "  shunted "  motions  affect  the  organism  it  be- 
comes a  conscious  sensation,  evoking  at  first  no  definite  mo- 
tion except  perhaps  diffusion,  if  profound  enough  evinced  in 
trembling,  etc.  In  fact,  the  secondary  ganglia  apparatus  is  a 
diffusive  apparatus,  and  we  may  so  regard  it.  It  is  filled  with 
embryonal  fibrillae,  which  are  acted  upon  in  all  directions  dif- 
fusively, but  which  do  not  exert  any  definite  effect  until 
through  least  resistance  the  plexus  forms  a  tract  which  serves 
a  useful  purpose.  As  everything  in  discrimination  or  judg- 
ment depends  upon  association,  it  is  easily  seen  how  this 
could  result  in  making  many  errors.  For  instance,  two  simul- 
taneously occurring  impressions  build  up,  from  the  brain 
plexus  of  fibrils,  a  tract  which,  by  associated  action,  dominates 
the  motions,  excites,  say,  the  feeling  of  fear.  Now,  while  this 
simultaneity  may  occur,  the  association,  objectively,  may  be 
purely  accidental,  and  the  animal  will  run  from  an  impression 
which  has  no  harmful  reality.  Eventually,  through  differen- 
tiation and  the  greater  persistence  of  the  truly  harmful  impres- 
sion without  the  harmless  one,  a  modified  tract  dissociates  the 
two,  and  by  this  process  of  integration,  disintegration  and  re- 
integration,  all  acts  of  all  animals  with  nervous  systems  are 
regulated.  Consciousness,  growing  from  the  chemical  affin- 
ities, increases  in  direct  ratio  with  the  masses  of  molecules 
acted  upon,  with  the  intensity  of  the  chemical  reactions  of 
such  molecules ;  but  the  consciousness  of  the  organism  can 


IO2  CLEVENGER — Physiology  and  Psychology. 

only  become  such  through  the  associated  commissural  union 
of  such  chemical  molecular  changes,  and  the  greater  and 
more  definite  this  union,  the  greater  and  more  definite  is  con- 
sciousness. 

Change,  difference  through  resistance,  and  the  necessity  for 
overcoming,  render  consciousness  more  acute ;  and  when, 
through  adjustment  of  the  molecules  into  the  least  resistant 
methods  of  working,  consciousness  passes  into  instinct,  reflex 
motions  thus  instituted  become  inevitable  ones,  and,  acting 
less  vehemently  upon  the  sensory  cells,  do  not  excite  con- 
sciousness at  all,  or  but  very  little. 

As  psychic  and  physical  life  are  inseparable,  the  mind  has 
merely  developed  as  a  complex  upon  the  better  and  still  better 
method  of  conserving  the  physical.  Many  mistakes  occur  in 
this  endeavor ;  but,  nevertheless,  that  is  the  intent  of  the  mind. 
That  failures  are  made  is  shown  by  disease  and  premature 
death ;  but  the  survival  of  forms  shows  that  they  have  adapted 
inner  to  outer  relations  more  or  less  effectually. 

The  senses  are  but  relative  forms  of  motion,  and  are  unclas- 
sifiable  except  as  they  manifest  themselves  in  groups,  such  as 
the  common  five  senses.  A  sense  may  be  any  molecular  mo- 
tion possible  to  a  cell,  or  at  first  not  possible,  but  into  which  it 
may  develop,  providing  such  motion  produces  profound  enough 
impressions  and  serves  a  useful  purpose  by  association.  In 
forms  in  our  phylum  the  olfactory  was  at  first  most  important, 
but  other  senses  have  superseded  it,  and  "  shunting  "  is  pro- 
gressing at  such  a  rate  that  this  originally  peculiar  tactile  cili- 
ated cell-motion  has  become  very  obtuse  in  man,  and  few  fibrils 
project  through  the  olfactory  nerves  to  unite  with  other  strands, 
and  such  as  have  originally  done  so  are  being  diverted  in  the 
formation  of  more  active  sense  fasciculi.  This  development 
and  destruction  of  sense  is  obvious  everywhere  among  men 


CLEVENGER — Physiology  and  Psychology.  103 

who  become  obtuse  to  certain  impressions  and  develop  extra- 
ordinary susceptibility  to  others.  The  auditory,  another  dif- 
ferentiated ciliary  tactile,  has  developed  to  an  important  posi- 
tion in  life  conservation,  and  the  optic  has,  through  constant 
correction  of  the  olfactory  errors,  absorbed  in  its  tracts  an  im- 
mense number  of  fibrils. 

Correction  of  one  sense  by  another  is  of  momentary  occur- 
rence, most  marked  in  awakening  from  sleep.  The  faint  exci- 
tations of  the  registered  impressions,  through  undue  relativity 
of  their  action  over  the  modes  of  impression  while  asleep, 
seem  real  to  us,  but  after  a  startling  dream  we  look  about  and 
correct  the  impressions  aroused  in  memory  which  were  taken 
for  genuine  ones,  and  which,  by  our  surroundings,  we  now  see 
were  not  so. 

This  constant  antagonism  of  one  sense  by  another  would 
tend  to  enfeeble  the  erroneous  impressions  brought  in,  and  the 
correction  would  entail  the  breaking  down  of  nerve  strands 
formerly  operative,  and  the  building  up  of  new  ones  in  the  en- 
tire line  of  animals,  on  the  basis  of  better  adaptation  ;  and  as 
these  adaptations  vary  to  such  an  extent  that  no  two  animals 
of  the  same  species  and  no  two  persons  are  alike,  then  no  two 
brains  can  be  alike  except  in  such  matters  as  are  common  to 
all  or  to  many.  The  musician's  brain  will  differ  in  fiber  distri- 
bution from  the  painter's,  and  the  mechanic's  from  the  labor- 
er's. The  civilized  man  will  possess  more  "  shunt "  and  dis- 
criminative diffusion  fibrils  than  the  savage.  And  in  precise 
ratio  of  intelligence  of  all  animals  do  we  see  the  cortical  neu- 
roglia  encroached  upon  by  fibrillar  creation. 

There  is  a  constant  struggle  on  the  part  of  higher  strands  to 
usurp  the  places  of  the  lower ;  and  the  reason  for  it  is,  that  with 
the  persistence  of-  higher  impressions  in  correction  of  thex 
lower,  the  correction  tendency  builds  up  higher  tracts  toward 


1 04  CLEVENGER — Physiology  and  Psychology. 

lower  planes.  Were  this  to  be  fully  accomplished,  and  no 
more  impressions  received  by  the  animal  than  those  to  which 
perfect  instinctive  adjustment  had  been  made,  then  conscious- 
ness would  cease,  and  the  animal  become  an  automaton  indeed  ; 
but  the  eternal  evolution  and  involution  of  things  prevents  this, 
and  advance  must  occur  or  death,  one  or  the  other.  The  very 
conditions  of  our  existence  demand  the  perpetual  change  of 
adaptation  to  perpetually  recurring  change  of  environment. 
Such  changes  constitute  the  impression  and  cease  to  be  ex- 
perienced in  consciousness  as  soon  as  perfectly  adapted  to. 
The  rabble  are  for  the  most  part  thus  adjusted,  and  tend  to  ex- 
hibit the  automatic  vegetative  life  with  dullness  of  reason. 

The  environment  which  has  reacted  to  arrange  species 
identity  has  built  up  a  common  morphology ;  a  generic  resem- 
blance in  brains  exists,  dependent  upon  a  generic  common  ex- 
perience and  general  resemblance  of  other  parts  made  by  the 
same  law ;  but  when  a  family  or  succession  of  individuals  live 
in  a  similar  environment  differing  from  that  of  the  species, 
variations  necessarily  befall  them,  and  inevitable  retrograde 
or  evolutionary  changes  proceed.  This  culminates  in  degra- 
dation on  one  hand  and  development  of  character  or  intellect 
upon  the  other,  with  concomitant  change  of  brain  minutiae. 

No  sooner  does  the  animal  find  itself  susceptible  to  certain 
impressions  that  are  of  no  life-conserving  use  to  it,  than  the 
diffusion  channels  in  the  brain  over  which  these  impressions 
pass  are  exercised  and  consciousness  evoked  to  the  extent  of 
producing  wonder,  an  arrest,  may  be,  of  other  motions,  occa- 
sional doubts,  shudders,  tremblings,  the  eyes  are  opened  wider 
to  admit  of  better  sight,  a  diffusion  effect;  and  if  at  any  time, 
either  by  accident  or  by  persistent  giving  up  to  the  exercise  of 
the  wonder  impressions  such  impressions  are  turnedto  account, 
the  after  tendency  will  be  to  repeat  the  act  upon  revival  of  the 


CLEVENGER — Physiology  and  Psychology.  105 

impression,  and  step  by  step  the  useful,  through  association, 
becomes  established  and  the  useless  held  in  check.  But  it  does 
not  always  happen  ;  indeed,  in  but  comparatively  few  instances 
does  it  happen  that  such  integrations  occur,  and  out  of  the 
countless  billions  of  useless  diffused  impressions  a  few  thousand 
cohere  in  this  way,  and  out  of  this  few  thousand  many,  if  not 
most,  suffer  dissociation  through  alteration  of  circumstances 
of  environment  or  separation  into  new  associations.  For  in- 
stance, an  association  may  be  formed  on  the  supposition  (me- 
chanically wrought  out  line  of  least  resistance)  that  a  certain 
sound,  scent  or  sight  inures  to  the  animal's  advantage.  This  may 
be  a  gross  mistake  ;  and  suddenly  it  is  discovered  as  such, 
through  association  with  some  fright  experience.  For  thus 
the  association  begins  to  disintegrate,  the  fibrils  set  in  new  di- 
rections, and  the  last  most  powerful  impression  reassociates  the 
strands,  the  thoughts,  instincts,  and  reflexes. 

Suppose  a  worm  were  to  be  often  hurt  by  stones  falling  upon 
it,  the  peculiar  tremors  induced  by  the  stone  in  falling  would 
be  associated  with  the  memory  of  pain,  and  it  would  shrink 
thereafter  upon  the  noise,  even  though  no  stone  fell. 

Association  is  induced,  as  often  before  remarked,  herein,  by 
simultaneity  of  impressions.  If  A  and  B  arouse  the  feeling  of 
pain,  they  cause  a  composite  sensation  which  either  A  or  B  may 
arouse  by  this  former  simultaneity.  We  do  not  stop  to  ana- 
lyze cur  sensations  any  more  than  the  savage  does.  Two 
things  occurring  together  de  novo  are  likely  to  be  accepted  as 
part  of  one  another,  and  association  is  the  simultaneous  sen- 
sation aroused,  and  is  a  simple  term  until  subsequent  dissocia- 
tion analyzes  the  two  impressions  through  a  mental  sense  cor- 
rection. 

In  the  worm  the  associations  were  mostly  tactile ;  next,  feebly 
optic,  with  tactile  and  rudimentary  auditory,  olfactory  and 


106  CLEVENGER — Physiology  and  Psychology. 

possibly  gustatory,  as  far  as  Darwin's  researches  allow  us  to 
judge. 

Analogy  shows  us  that  the  social  organism  has  the  most 
primitive  pain  and  pleasure  ideas  at  first,  acts  upon  alarms  and 
jubilantly  on  the  least  occasion.  It  is  also  at  war  with  itself, 
and  so  the  units  of  the  organism  war  with  each  other,  except 
where  their  workings  are  the  most  obviously  egoistic.  The 
units  are  bound  together  blindly  by  their  selfish  instincts,  as 
are  the  lowest  natures.  The  cell  works  harmoniously  with  the 
neighboring  cell  from  which  it  derives  its  food ;  the  cat  and 
dog  say  to  the  kitchen-maid  who  feeds  them,  as  the  child  says 
to  its  mother,  "I  love  you." 

Altruism  springs  from  and  is  a  developed  egoism.  The  or- 
ganism which  acts  intelligently,  altruistically,  knows  that  it  de- 
rives advantages  from  so  doing  which  the  lower,  pure  egoistic 
worker  i<  incapable  of  understanding. 

Consciousness  diminishing  in  proportion  to  the  outlet  in 
activity  for  impressions  is  well  shown  when  pain  (dissonant  cell 
motion)  is  assuaged  by  motion.  In  grief,  one  is  impelled  to 
walk  about,  move  the  arms,  gesticulate,  exclaim  ;  and  any  mo- 
tion affords  some  relief.  When  the  pain  is  increased  by  mov- 
ing, it  is  through  the  direct  interference  of  the  moving  parts 
with  nerve  elements,  and  has  no  reference  to  such  conditions  as 
allow  motion  to  allay  pain. 


CLEVENGER — Physiology  and  Psychology.  1 07 


CHAPTER    VI. 
PHYSICS  OF  THE  CEREBRO-SPINAL  NERVOUS  SYSTEM. 

The  olden  division  of  the  senses  into  five  must  give  way  to 
a  broader  classification,  and  Tyndallian  physics  must  be  ap- 
pealed to  to  widen  our  knowledge  of  the  subject. 

The  reader  should  consult  Herbert  Spencer  for  an  elegant 
description  of  the  rythm  and  undulations  which  pervade  all 
nature.  He  points  out  the  up  and  down  movements  of  atoms, 
molecules  and  grosser  matter  in  light  vibrations,  sound  waves, 
mechanical  motion  in  the  stellar  universe,  in  plant  and  animal 
life,  in  sensation,  in  our  feelings,  emotions  and  reasoning  pow- 
ers. Everywhere  we  turn  we  find  action  and  reaction.  Indi- 
viduals and  nations  at  one  time  in  the  greatest  turmoil,  and  at 
another  time  apathetic.  One  day  we  are  capable  of  putting 
forth  a  great  amount  of  energy,  and  upon  succeeding  days  our 
faculties  seem  dulled,  and  so  on  everywhere. 

These  all-pervading  motions  constitute  sensation  whenever 
they  affect  the  organism  cell  to  the  extent  of  causing  motion 
in  them.  This  may  seem  a  sweeping  claim,  but  it  is  justified 
in  our  inability  to  separate  the  psychic  from  the  physical  life. 

In  protozoa  and  metazoa  without  nerves  it  is  plain  that  each 
cell  presenting  a  modicum  of  its  undifferentiated  originality 
must  act  as  a  sensory  cell  to  a  greater  or  less  extent  whenever 
the  molecules  of  such  cell  moved. 

As  the  cell  motions  become  coordinated  by  an  evolved  ner- 
vous system  with  higher  and  still  higher  integration  and  sep- 
aration of  cell  labor  into  districts,  the  molar  activities  of  the 
organism  separated  from  the  sensory,  and  while  in  every  ani- 


io8  CLEVENGER — Physiology  and  Psychology. 

mal,  however  highly  organized,  the  cellular  senses  remain  as 
in  the  primitive  form,  such  senses  have  nothing  to  do  with  those 
of  the  organism  until  internuncially  related  through  the  nerves. 
This  may  be  better  understood  by  regarding  the  condition 
known  as  anaesthesia.  Where  an  injury  to  the  sensory  tracts 
occurs  the  parts  from  which  such  tracts  proceed  "  lose  their 
sensation."  The  animal,  as  a  whole,  is  no  longer  apprized  of 
what  occurs  in  the  division  dissociated. 

Modern  physics  afford  us  measurements  of  the  motions 
occurring  in  such  phenomena  as  light  and  sound,  and  glimpses, 
through  analogy,  of  other  energies. 

Taking  them  seriatim  we  can  best  picture  them  as  having 
wave  lengths  varying  from  the  infinitely  small  to  the  infinitely 
large,  even  though  we  are  unable  to  conceive  of  infinity.  We 
can  strike  an  approximate  measurement  for  some  forces  and 
for  others  exact  ones  have  been  found  for  us. 

Gravitation  stands  at  the  head  of  the  list  as  acting  upon 
every  atom  with  a  force  inversely  as  the  square  of  the  distances 
and  directly  as  the  masses.  La  Place  calculates  the  rapidity  of 
gravitation  to  be  at  least  seven  million  times  that  of  light,  for 
its  interplanetary  attraction  is  instantaneous,  /Xio6X  the 
speed  of  the  violet  ray  per  second,  757  X  io12,  gives  us  the 
enormous  rate  of  52QQX  io18. 

Chemical  energy  apparently  merges  into  this  from  the  fluor- 
escent end  of  the  spectrum,  though  we  must  make  room  for 
electricity  as  a  vibratory  force.  Approximately  where  we  can- 
not be  precise,  and  exactly  where  science  justifies  us  in  our 
figures,  we  may  tabulate  the  forces  as  follows  : 

Gravitation 5XIO21  ±  to  -j- 

Electricity io15  ±  to     5Xio21± 

Chemism 757XIO12  ±  to  io16  ± 

Light 3Q2XI012       to  757XI012 


CLEVENGER — Physiology  and  PsycJwlogy.  109 

Heat io8   ±  to  io12 

Sound 40         to     4  X  io4 

Mechanical  waves 30         to  — 

But  these  forces  interlace  in  many  instances  much  more 
than  can  be  shown  in  such  a  rude  summary.  For  instance, 
fluorescence  resides  not  only  in  the  ultra  violet  ray  with  other 
actinic  or -chemical  energy,  but  the  latter  extends  into  the 
spectrum  toward  the  less  refrangible  rays.  Heat  extends  into 
the  ultra  red  ray.  Sound  and  molar  force  have  the  same  rates, 
grossly  evident  in  low  notes  and  less  apparent  in  high  ones. 
Then,  to  complicate  matters  still  more,  certain  nitrites  may  be 
exploded  by  musical  notes  to  which  their  molecules  are  disrup- 
tively  attuned.  We  can  only  indicate  these  forces  by  such 
figures,  and  must  leave  a  fuller  consideration  of  them  to  the 
physicists.  The  main  point  to  which  I  wish  to  attract  atten- 
tion is  the  somewhat  serial  vibratory  nature  of  all  the  energies: 
gravitation,  chemism,  electricity,  having  wave  lengths  smaller 
and  velocities  greater  than  light.  Heat  and  sound  waves  being 
longer  and  their  speeds  less  than  light  rays,  and  the  mechan- 
ical waves  passing  from  invisibility  in  size  to  such  monstrous 
dimensions  as  we  can  see  them  rolling  on  the  sea,  and  beyond 
this  to  such  as  are  produced  by  orbital  perturbations  of  planets 

Natural  selection  has  adjusted  the  cell  contents  to  certain 
vibrations ;  and  as  fast  as  evolution  adapted  these  vibrations 
toward  life-subserving  processes,  it  mattered  nothing  in  the 
end  to  be  attained  as  to  whether  those  waves  were  appreciated 
as  sensations  useful  to  the  organism  or  accomplished  some 
other  and  different  method  of  perpetuating  cell  life,  or  whether, 
which  is  often  the  case,  the  same  modes  of  motion  were  useful 
in  two  or  several  ways  simultaneously.  This  is  one  of  the 
many  evidences  of  the  impossibility  of  separating  sensation 
from  general  molecular  energy.  We  are  compelled  to  select 


i  io  CLEVENGER — Physiology  and  Psychology. 

out  such  as  are  more  plainly  concerned  in  sensory  operations, 
with  the  reservation  that  sensation  is  purely  a  relative  matter 
in  its  divisions.  It  is  hard  to  say  where  one  sense  ends  and 
another  begins.  In  the  cases  of  touch  and  hearing  in  low 
notes  and  mechanical  vibrations  of  about  30  per  second,  both 
senses  appreciate  the  same  thing. 

Sir  John  Lubbock  has  demonstrated  the  ability  of  "lower" 
animals  to  be  affected  by  vibrations  ultra  spectral  and  ultra 
acoustic.  Man,  thus,  has  either  lost  or  never  possessed  faculties 
which  other  animals  retain  or  may  have  differentiated.  Indi- 
viduals vary  between  themselves  in  their  ranges.  Most  per- 
sons "have  an  ear"  only  for  notes  to  16,000  vibrations  per 
second,  while  the  possible  range  is  placed  at  38,000. 

In  default  of  observations  which  would  have  established  the 
gradations  as  they  arose,  we  cannot  conveniently  dwell  upon 
the  evolution  of  the  senses  except  in  a  cursory  way. 

Light,  heat  and  sound  affect  the  protozoon,  but  with  the 
gradual  organ  construction  better  defined  methods  for  their 
appreciation  arose. 

Impressed  with  the  fact  that  everything  in  our  intellectual 
lives  depends  on  or  grows  out  of  our  sensations,  David  Hart- 
ley, a  disciple  of  Locke,  addressed  himself  to  a  study  of  the 
mental  mechanism  in  the  last  century,  when  the  anatomy  and 
physiology  of  the  nervous  system  were  but  imperfectly  known. 

The  Aristotelian  dictum  which  recognized  the  dependence 
of  intellect  upon  the  senses,  until  Hartley's  day  stimulated  but 
few  efforts  to  explain  the  intimate  workings  of  animal  machi- 
nery through  direct  study  of  its  parts. 

The  surmises  of  Descartes  and  Hume  were  excellent,  but 
Hartley's*  inferences  from  observations  of  nervous  physiology 

^Observations  on  Man ;  His  Frame,  His  Duty,  and  His  Expectations,  pp. 
756.  London,  1749. 


CLEVENGEK — Physiology  and  Psychology.  1 1 1 

are  unparalleled,  considering  the  crude  knowledge  of  his  time. 
His  theory  of  vibrations  was  an  application  of  Sir  Isaac  New- 
ton's, whose  personal  acquaintance  he  enjoyed. 

The  sense  organs  and  the  nervous  system  are  to  be  con- 
sidered together.  To  Herbert  Spencer  we  are  indebted  for  a 
correct  synthetical  method  of  so  doing,  and  however  widely  of 
the  mark  he  may  have  fallen  in  many  instances,  through  the 
necessity  of  his  plan  in  seeking  ultimates,  the  ground-work  of 
Spencer's  Synthetic  Philosophy  will  inspire  thinkers  to  the  end 
of  time. 

In  his  data  of  psychology*  he  reviews  the  structure  and 
functions  of  the  nervous  system,  the  conditions  essential  to 
nervous  action,  aestho-physiology,  and  the  scope  of  psychol- 
ogy. We  may  advantageously  epitomize  some  of  the  points 
he  urges : 

"While  the  rudimentary  nervous  system,  consisting  of  a  few 
threads  and  minute  centers,  is  very  much  scattered,  its  in- 
crease of  relative  size  and  increase  of  complexity  go  hand  in 
hand  with  increased  concentration  and  increased  multiplicity 
and  variety  of  connections. 

"  Isomerism  seems  to  be  the  molecular  change  undergone 
in  nerve  activity. 

"Gray  matter  contains  five  times  as  many  capillaries  as 
white  "  (based  on  cubed  averages  from  Kolliker's  plates);  from 
this  he  infers  greater  composition  and  decomposition  in  gray 
areas. 

"  Conditions  essential  to  nervous  action  are : 

"  Continuity  of  nerve  substance. 

"Absence  of  much  pressure. 

"  Heat  kept  above  a  certain  level,  limited. 

"  Suitable  quantity  and  quality  of  blood  supply. 

"  Minimum  presence  in  blood  of  CO2,  urea,  and  other  toxic 
agents. 

*Principles  of  Psychology,  Vol.  I.,  Chap.  i.  to  vii. 


1 1 2  CLEVENGER — Physiology  and  Psychology. 

"  Waste  must  be  fully  met  by  repair. 

"  Nerve  is  not  capable  of  continuous  stimulation  or  contin- 
uous discharge. 

"  The  transmission  of  a  disturbance  through  a  nerve  takes 
an  appreciable  time. 

•'  Every  wave  of  isomeric  transformation  passing  along  a 
nerve-fiber  entails  on  it  a  momentary  unfitness  to  convey  an- 
other wave,  and  it  recovers  its  fitness  only  when  its  lost  mo- 
lecular motion  has  been  replaced,  and  its  unstable  state  thus 
restored. 

"  Every  part  of  the  nervous  system  is  every  instant  trav- 
ersed by  waves  of  molecular  change — here  strong  and  there 
feeble.  There  is  a  universal  reverberation  of  secondary  waves 
induced  by  the  primary  waves  now  arising  in  this  place  and 
now  in  that,  and  each  nervous  act  helps  to  excite  the  general 
vital  processes  while  it  achieves  some  particular  vital  process. 
The  recognition  of  this  fact  discloses  a  much  closer  kinship 
between  the  functions  of  the  nervous  system  and  the  organic 
functions  at  large  than  appears  on  the  surface.  Though  un- 
like the  pulses  of  the  blood  in  many  respects,  these  pulses  of 
molecular  motion  are  like  them  in  being  perpetually  generated 
and  diffused  throughout  the  body,  and  they  are  also  like  them 
in  this,  that  the  centrifugal  waves  are  comparatively  strong, 
while  the  centripetal  waves  are  comparatively  feeble.  To 
which  analogies  must  be  added  the  no  less  striking  one  that 
the  performance  of  its  office  by  every  part  of  the  body,  down 
even  to  the  smallest,  just  as  much  depends  on  the  local 
gushes  of  nervous  energy  as  it  depends  on  the  local  gushes  of 
blood. 

"  Higher  animals  possess  greater  self-mobility. 

"Whenever  much  motion  is  evolved,  a  relatively  large  ner- 
vous system  exists. 

"Whenever  the  motion  evolved,  though  not  great  in  quan- 
tity, is  heterogeneous  in  kind,  a  relatively  larger  nervous  sys- 
tem exists. 

"Whenever  the  evolved  motion  is  both  great  in  quantity 
and  heterogeneous  in  kind,  the  largest  nervous  systems  exist. 


CLEVENGER — Physiology  and  Psychology.  1 1 3 

"Stimuli  of  all  orders  produce  effects  alike  for  like  nerves.'' 

We  may  safely  posit  what  has  here  been  quoted,  the  isom- 
erism  of  nerve  substance  excepted,  as  needing  more  defence 
though  satisfying  many  requirements.  Few  have  shown  the 
catholicity  of  Spencer  in  biological  philosophy,  and  it  would 
be  well  for  every  investigator  to  imbibe  some  of  his  spirit  be- 
fore advancing  or  condemning  theories  of  mental  action.  Hume 
would  rejoice  in  the  immensity  of  psychological  data  we  to- 
day possess,  based  upon  dimensions  and  intervals  of  time, 
but  which  sadly  need  a  Copernicus  or  Newton  to  assimilate 
them. 

So  far  as  objective  phenomena  are  concerned,  the  vibratory 
theory  affords  the  only  practical  and  satisfactory  explanation 
of  universal  phenomena  to  chemists,  electricians,  and  physicists 
generally.  Millions  of  dollars  are  daily  invested  by  capitalists 
upon  the  accuracy  of  deductions  from  the  vibratory  theory  in 
the  mercantile  fields  of  telegraphy,  telephony,  optics,  chemistry, 
music,  etc. 

Schwalbe  *  affirms  laws  regulating  the  size  of  nerve-fibers. 
He  found  a  physiological  distinction,  e.  g.,  motor  or  sensi- 
tive, influences  the  size  of  the  fibers,  and  he  adopts  M.  Pierret's 
law  that  the  size  of  the  cell  and  thickness  of  the  nerve  roots 
are  regulated  by  the  distance  at  which  its  nervous  influence  is 
exerted,  corresponding  to  Dieter's  claim  that  the  size  of  the 
cell  is  in  proportion  to  the  thickness  of  the  proceeding  axis 
cylinder.  The  brain  exhibits  fewer  size  variations  than  the 
spinal  cord.  These  variations,  Schwalbe  states,  have  reference 
to  the  size  of  the  animal,  extent  of  distribution,  physiological 
attributes  of  the  nerve,  and  the  amount  of  usage  to  which  it 
ministers. 

Spitzka,f  discussing  the  erroneous  notion  that  function  and 
cell-size  were  related,  is  willing  to  predicate  for  the  so-called 
motor  cell  but  one  character,  "  that  the  transition  from  the 
body  to  the  processes  is  so  gradual  that  it  is  difficult  to  say 

*  On  the  Relations  of  the  Calibre  of  Nerve  Fibers.     Leipzig,  1882. 
f  Journal  of  Nervous  and  Mental  Disease.     April,  i881,  p.  325. 


1 14  CLEVENGER — Physiology  and  Psychology. 

when  the  body  ends  and  the  process  begins,  while  in  unques- 
tionably sensory  cells  the  transition  is  always  abrupt."  Al- 
though in  some  areas  sensory  cells  are  larger  than  adjacent 
motor  cells,  as  a  general  rule  the  motor  cell  is  relatively  larger 
than  neighboring  sensory  cells ;  but,  as  Spitzka  shows,  this 
must  be  accepted  with  reservations. 

Hoffman*  affords  us  some  careful  measurements  of  nuclei, 
nerve  cells  and  fibrillae,  but,  in  common  with  Spitzka,  Ranvier, 
Meynert,  and  other  exact  observers,  affirms  nothing  on  the 
strength  of  mere  size. 

The  nervous  system  does  not  differ  materially  from  other 
tissues  in  development.  Heterogeneity  of  function  brings 
about  a  quantitative  rather  than  a  qualitative  increase,  and  the 
only  relationship  between  size  and  function,  in  my  opinion,  is  a 
nutritional  one.  Coeteris  paribus,  thick  axis  cylinders  afford 
less  resistance  than  thin  ones,  and  use  either  in  frequency  or  in- 
tensity, or  both,  would  determine  sizes  between  nerve-cells  and 
fibrillcz  of  the  same  ages,  lengths,  locations,  etc.,  without  regard 
to  motor  or  sensory  differentiation. 

The  great  similarity  between  terminal  fibers  in  their  distri- 
bution to  various  organs,  muscular,  glandular,  etc.,  admit  of 
no  other  explanation  than  that  the  work  accomplished  by 
nerves  does  not  depend  so  much  upon  the  kind  of  stimulus  or 
nature  of  the  nerve  elements  as  upon  the  character  of,  and 
possibilities  inherent  in,  the  non-nervous  organs  to  which  they 
are  related. 

The  first  appearance  of  contractile  tissue  left  the  primitive 
animal  mass  responsive  to  undifferentiated  motions  and  sensa- 
tions. Every  jar  or  impact,  every  change  of  temperature  or 
transition  of  light  and  shade,  acted  to  stimulate  the  rudiment- 
ary muscular  tissue.  Adjustment  to  the  environment  determ- 
ined to  which  of  these  stimuli  response  would  be  most  apt  to 

*  Journal  of  Neurology  and  Psychiatry.     August,  1883. 


CLEVENGER — Physiology  and  Psychology.  115 

occur,  precisely  such  adjustment  and  readjustment  as  man  in 
common  with  other  animals  undergoes  daily.  Definite  sar- 
codal  contractions  were  followed  by  the  definition  of  a  path 
for  stimuli  through  least  resistance  lines. 

Kleinenburg's  neuro-muscular  development  of  hydra  Hux- 
ley* mentions  as  internuncial,  and  the  primitive  form  of  a  nerve. 
Eimerf  observed  in  the  Ctenophora,  the  mesoderm  traversed 
in  all  directions  by  very  fine  fibrils  varying  in  diameter  from 
-STSVUIS  to  TThra  of  an  inch.  These  fibrils  take  a  straight  course, 
branch  dichotomously,  and  end  in  still  finer  filaments,  which 
also  divide,  but  become  no  smaller.  They  terminate  partly  in 
ganglionic  cells,  partly  in  muscular  fibers,  and  partly  in  the 
cells  of  the  ectoderm  and  endoderm.  Many  of  the  nerve-fibrils 
take  a  longitudinal  course  beneath  the  center  of  each  series  of 
paddles,  and  these  are  accompanied  by  ganglionic  cells  which 
become  particularly  abundant  toward  the  aboral  end  of  each 
series.  The  eight  bands  meet  in  a  central  tract  at  the  aboral 
pole  of  the  body;  but  Eimer  doubts  the  nervous  nature  of  the 
cellular  mass  which  lies  beneath  the  lithocyst  and  supports  the 
eye-spots.  (En  passant,  this  dichotomy  of  nerve-fibrils  agrees 
with  Schultze's  observations.];)  Hubrecht||  describes  a  new 
worm,  "  Pseudonematon  nervosum,  without  trace  of  sexual, 
excretory,  or  sensory  organs,  with  three  muscular  layers,  con- 
sisting of  a  thick  external  longitudinal,  a  middle  transverse  or 
circular,  and  an  internal  longitudinal  layer.  The  nervous  sys- 
tem forms  a  continuous  layer  completely  around  the  body, 
lying  immediately  inside  the  layers  of  muscular  fibers.  It 
consists  of  (i)  a  fine  network  of  delicate  filaments,  appearing 
as  if  felted,  barely  tinged  by  the  staining  reagents,  and  (2)  of 
scattered  nuclei,  belonging  partly  to  connective  tissue,  partly 
to  ganglion  cells.  The  layer  forms  a  continuous  tube  from  the 
head,  where  there  is  no  ganglionic  enlargement,  back  through 

*  Anatomy  of  Invertebrated  Animals,  1878,  p.  62. 
f  Zoologische  Studien  auf  Capri,  Leipsic,  1873. 
J  Archiv  fur  Anatomic  und  Physiologic,  1878. 
||  American  Naturalist,  May  i884,  p.  546. 


Ii6  CLEVENGER — Physiology  and  Psychology. 

the  body  to  the  caudal  region,  where  the  layer  is  present 
dorsally  only." 

Darwin's*  ascription  of  intelligence  to  earth-worms  does  not 
involve  the  organization  of  a  sensory  distribution.  Sounds 
produce  waves  in  the  undifferentiated  sensorium,  and  alter  the 
usual  molecular  interchanges.  Light  stimulates  the  cerebral 
ganglia  of  the  worm  without  the  intervention  of  a  sense  organ, 
owing  to  its  diaphanous  skin.  Darwin  finds  evidences  of  ol- 
factory and  gustatory  appreciation,  but  the  tactile  sense  is  the 
main  one. 

Gegenbaurf  assigns  a  high  development  of  tactile  sense 
organs  to  vermes,  but  the  visual  organs  of  different  species  af- 
ford evolutionary  variations.  Those  of  the  rotatoria  are  placed 
directly  upon  the  cerebrum  with  a  crystalline  rod  to  each  pig- 
ment spot,  or  the  latter  is  present  alone.  Among  coelenterata, 
spongiae  have  no  sensory  organs,  neither  have  the  low  forms 
of  acalaphse.  The  cellular  layer  of  the  hydroid  polyps  is  an 
undifferentiated  organ  of  sensation. 

"  Balfour  J  states  that  "  embryological  evidence  shows  that 
the  ganglion  cells  of  the  central  part  of  the  nervous  system 
are  originally  derived  from  the  simple  undifferentiated  epithelial 
cells  of  the  surface  of  the  body,  while  the  central  nervous  sys- 
tem itself  has  arisen  from  the  concentration  of  such  cells  in 
special  tracts. 

"  The  nervous  system  of  the  higher  metazoa  appears  to  have 
been  evolved  in  the  course  of  a  long  series  of  generations  from 
a  differentiation  of  some  of  the  superficial  epithelial  cells  of  the 
body,  though  it  is  possible  that  some  parts  of  the  system  may 
have  been  formed  by  a  differentiation  of  the  alimentary  epithe- 
lium. 

"An  early  feature  of  the  differentiation  consisted  in  the  growth 
of  a  series  of  delicate  processes  of  the  inner  ends  of  certain  epi- 


*  Formation  of  Vegetable  Moulds  through  the  Action  of  Worms,  with  Obser- 
vations on  their  Habits,  1883 

f  Comparative  Anatomy:  Bell  and  Lank  ester  tr  ,  1878,  p.  152. 
^Comparative  Embryology,  1881,  p.  333. 


CLEVENGER — Physiology  and  Psychology.  1 1 7 

thelial  cells,  which  became  at  the  same  time  specially  differen- 
tiated as  sense  cells. 

"  These  processes  gave  rise  to  a  sub-epithelial  nervous  plexus 
in  which  ganglion  cells,  formed  from  sense  cells  which  traveled 
inwards  and  lost  their  epithelial  character,  soon  formed  an  im- 
portant part. 

"  The  central  nervous  system  was  at  first  continuous  with 
the  epidermis,  but  became  separated  from  it,  and  traveled  in- 
wards." 

Nerves,  such  as  we  find  them  in  the  higher  types,  originated 
from  special  differentiations  of  the  nervous  network  radiating 
from  the  parts  of  the  central  nervous  system. 

Balfour  admits  two  points  as  obscure  : 

1 .  "  The  steps  by  which  the  protoplasmic  process  from  the 
primitive  epidermic  cells  became  united  together  so  as  to  form 
a  network  of  nerve-fibers,  placing  the  various  parts  of  the  body 
in  nervous  communication. 

2.  "  The  process  by  which  nerves  become  connected  with 
muscles,  so  that  a  stimulus  received  by  a  nerve  cell  could  be 
communicated  to  and  cause  a  contraction  in  a  muscle.     The 
primitive  relations  between  the  nervous  network  and  the  mus- 
cular cells  are  matters  of  pure  speculation." 

It  has  often  occurred  to  me  that  reasoning  fiom  analogies 
would  afford  clues  otherwise  unattainable.  It  is  incontestable 
that  the  proper  phosphorized  protagonous  composition  was 
acquired  by  ingestion  ;  it  lay  in  the  environment  of  the  low 
matazoon,  and  just  as  the  shell  of  the  snail,  or  more  palpably, 
the  envelope  of  foraminifera  was  excreted,  so  these  explosive 
compounds  were  externally,  ectodermally  diffused,  and,  being 
acted  upon  by  extrinsic  forces  in  lines  of  least  resistance,  be- 
came useful  in  discrimination  as  the  shell  became  protective, 
and  we  see  every  evidence  of  the  tendency  of  animals  to  per- 
petuate and  develop  and  differentiate  organs  which  may  have 
arisen,  and  in  all  probability  did  arise,  accidentally. 


1 1 8  CLEVENGER — Physiology  and  Psychology. 

The  pigment  spots  in  vermes  becoming  points  of  special 
irritation  develop  into  eyes. 

We  can  then  assume  that  special  chemical  alterations  oc- 
curring peripherally  were  appreciated  centrally  in  terms  of 
general  sensation,  that  is,  where  previously  jars  and  compara- 
tively coarse  waves  served  as  stimuli,  light  vibrations,  through 
chemical  decomposition  of  pigment,  brought  about  the  prim- 
itive irritability  constituting  sight. 

"  The  nervous  system  being  derived  from  the  epiblast  implies 
that  the  functions  of  the  central  nervous  system  which  were 
originally  taken  by  the  whole  skin  became  gradually  concen- 
trated in  a  special  part  of  the  skin,  which  was  step  by  step 
removed  from  the  surface,  and  has  finally  become  in  the  higher 
types  a  well-defined  organ  embedded  in  the  subdermal  tissues." 
(Op.  cit.) 

In  the  division  of  labor  by  the  tissues,  many  portions  fall 
below  the  average  irritability  by  changes  in  chemical  inapti- 
tudes, and  protoplasmic  parts  most  exposed  to  vibratory  impacts 
not  only  preserved  the  original  sensitiveness,  but  developed  it, 
as  every  organ  is  developed  by  use,  perpetuating  what  is  use- 
ful, and  eliminating  the  useless. 

Above  the  planula  stage  we  have  eminently  contractile  tis- 
sue aggregating  in  certain  parts,  and  in  others  cells  resisting 
differentiation  in  other  than  assimilative  directions,  the  highly 
irritable  ectodermal  eventually  forming  the  cerebro-spinal  axis. 
At  this  period,  internuncial  fibers,  such  as  nerves,  arising  in  a 
plexiform  manner,  would  fall  into  directions  regulated  by  lines 
of  least  resistance,  definite  motions  being  the  end  toward 
which  definite  structures  tended.  Muscular  tissue  is  that 
structure  which,  preserving  much  irritability,  developed  its 
contractile  powers,  and  became  more  efficient  through  linear 
arrangement  of  its  cells  and  their  connection  with  tissues  of 


CLEVENGER — Physiology  and  Psychology.  1 19 

some  degree  of  induration.  The  contiguity  of  the  highly  sen- 
sitive tissue  enabled  possible  conveyance  toward  the  contrac- 
tile of  stimulation  from  distant  parts  of  the  body.  This  is  the 
neuro-muscular  system  in  futuro.  It  is  well  not  to  mistake 
words  for  things,  and  not  designate  nerves  at  this  stage  as  sen- 
sory or  motor,  for  the  two  functions  seemed  combined  and  in- 
separable. Vibrations  are  conveyed  better  by  the  rudimen- 
tary nervous  tissue,  and  contraction  of  the  rudimentary  muscle 
is  the  result.  Such  peripheral  points  as  pigment  spots, 
through  chemical  susceptibility  greater  than  had  been  hereto- 
fore apparent  in  the  body  mass,  enabled  the  sensitive  tissue  to 
take  cognizance  of  new  irritations,  such  as  light  waves,  through 
the  conversion  of  such  waves  into  terms  of  general  sensitiveness. 
An  all-important  consideration,  and  one  whose  elaboration  will 
assist  clear  ideas  of  neural  differentiation.  In  the  Morse  code 
of  telegraphy,  the  dots  and  dashes  arranged  to  indicate  letters 
are  learned  as  indicating  words  or  impressions,  knowledge  of 
which  was  previously  acquired.  While  the  dot  and  dash 
sounds  were  not  new  to  the  ear,  their  definite  arrangement 
brought  us  en  rapport  with  a  new  experience  correlated  with 
pre-existing  appreciations.  Sunlight  existed  and  influenced 
the  protozoon,  but  as  soon  as  the  pigment  appearance  pro- 
duced new  terms  for  old  sensations,  a  revival  of  former  cur- 
rents through  a  new  influence,  the  recently  acquired  periphe- 
ral chemical  change  readjusted  the  life  possibilities  of  the 
animal,  appreciation  of  light  and  shade  became  possible,  inter- 
ruptions of  the  molecular  changes  thus  induced  by  association 
with  food  acquiring  or  enemy  escaping  motions  through  use 
and  natural  selection  grew  to  the  extended  importance  it  pos- 
sesses in  metazoon  existence.  The  pre-existing  neural  irrita 
bility  was  not  changed,  but  brought  through  peripherally 
increased  susceptibility  into  new  relations.  We  find  on  every 


1 20  CLEVENGER — Physiology  and  Psychology. 

hand  a  justification  for  this  analogical  reasoning.  Whenever 
a  new  discovery  or  invention  extends  the  range  of  man's  abili- 
ties, it  does  not  change  the  organism,  but  renders  it  capable  of 
new  applications  of  pre-existing  potencies. 

The  rapidity  of  impact  may  modify  subjacent  structure  so  as 
to  change  the  density  of  the  conveying  nerve,  but  the  close  re- 
semblance of  all  nervous  tissue  precludes  the  idea  of  any  great 
change  being  wrought  in  the  nerve  element  proper  through 
change  in  peripheral  sensibility. 

The  translation  into  terms  of  nerve  application  must  be  peri- 
pheral, as  it  is  initially  there  brought. into  relation  with  the 
former  general  sensibility.  It  is  not  necessary  to  consider  the 
organ  as  subsequently  dipping  below,  and  becoming  continu- 
ous from  skin  to  central  system,  and  mature  differentiation 
shows  us  structurally  that  the  centripetal  nerves  do  not  admit 
of  this  supposition.  They  may  undergo  slight  modifications 
due  to  the  times  of  impulses,  but  in  the  main  do  not  differ 
from  centrifugal  nerves. 

We  have  every  reason  to  believe  that  the  neuroglia  is  allied 
to  the  original  undifferentiated  irritable  protoplasm,  notwith- 
standing Huguenin,*  "a  tissue  which  increases  as  mental 
functions  decrease  cannot  be  the  medium  of  such  functions," 
for  as  differentiations  of  this  basis  substance  occurred  in  a 
higher  scale  of  intelligence,  it  is  the  very  substance  of  all  others 
to  be  encroached  upon  by  organization. 

The  contractions  and  expansions  of  masses  through  changes 
in  density  by  aggregation  and  seggregation  of  molecules  are 
familiar  chemical  reactions.  That  identical  molecular  translo- 
cations  constituted  the  irritability  and  automatism  of  living 
protoplasm  we  have  every  reason  to  believe. 

The  development  of  the  aggregating  and  seggregating  in- 

*  Allg.  Pathologic  der  Krankheiten  des  Nervensystems,  Zurich,  1873. 


CLEVENGER — Physiology  and  Psychology.  1 2 1 

stability  in  either  direction  would  inevitably  cause  a  separation 
of  such  over  susceptible  molecules  from  the  general  mass. 
The  eminently  aggregative  molecules  are  the  muscular.  The 
eminently  seggregative  molecules  are  the  nervous,  and  both  of 
these  are  developed  from  the  irritable  protoplasm,  which  as 
the  neuroglia  separates  off  into  ganglionic  areas,  and  through 
preservation  of  the  original  irritability  (antagonistic  seggrega- 
tive and  aggregative  molecular  power)  and  elimination  of  in- 
terfering matters,  it  has  become  the  seat  of  the  feelings,  the 
meeting  place  of  the  sensations,  the  part  to  which  waves  con- 
verge, and  from  which  they  diverge  in  the  institution  of  vital 

movement. 

The  general  sensibility  which  guides  the  muscular  contrac- 
tions when  the  central  nervous  system  became  the  conveyor 
of  general  sensibility,  its  connection  with  the  muscular  system 
would  follow,  and  whenever  exaltation  of  sensibility  occurred 
in  any  area,  centripetal  connection  with  the  seat  of  general  sen- 
sibility would  also  follow.  We  can  safely  grant  the  primitive 
central  neuroglia,  such  as  the  amphioxine,  a  general  suscepti- 
bility with  a  fixed  range  of  mechanical  and  chemical  irritabil- 
ity, the  gelatinous  quivers  and  molecular  motions  which  neces- 
sarily occur  as  conditions  of  its  existence. 

The  motor  nerves  respond  to  a  definite  group  of  these  vibra- 
tions through  habit  and  adjustment.  No  matter  how  these 
vibrations  may  be  produced,  we  know  that  when  they  occur 
they  stimulate  the  muscles  to  contraction.  The  uniform  range 
of  vibrations  within  the  compass  of  the  protoplasm  producing 
muscular  movements  necessitated  the  removal  of  motor  nerves 
from  chances  of  passing  stimuli,  and  hence  the  motor  nerves 
in  highly  organized  animals  are  related  to  the  central  nervous 
system,  but  not  to  the  periphery.  The  advantages  of  this  are 
apparent.  The  limited  field  of  disturbance  to  which  the  cere- 


122  CLEVENGER — Physiology  and  Psychology. 

bro-spinal  axis  or  the  protoplasmic  basis  substance  was  sub- 
ject served  the  motor  nerves  as  a  cut-off  for  impressions. 

The  somatic  motions  are  innumerable,  but  may  be  grouped 
as  molar  and  chemical.  The  molar  motions  are  the  circula- 
tory, and  those  made  by  the  limbs  and  body  generally  in  loco- 
motion, prehension,  or  any  other  change  of  relative  position  of 
parts  of  the  body,  regarded  by  Goethe  as  comprehending  all 
that  animals  could  do. 

The  atomic  interchanges  which  occur  in  every  cell  of  the 
body  produce  chemical  movements  of  complex  natures.  Res- 
piration, in  the  conversion  of  haemoglobin  into  oxyhaemo- 
globin,  is  chemical,  and  in  muscle  and  nerve  this  respiratory 
function  is  evident.  Oxygenation  of  the  tissues  is  an  accom- 
paniment of  life  in  all  cells.  It  is  a  nutritive  act,  and  the  sig- 
nificance of  oxygenation  is  no  greater  in  the  nerve  areas  than 
it  is  in  other  organs.  Hence  oxygen,  though  necessary  to 
nerve  action,  does  not  impart  that  action,  but  contributes  to  it. 
renders  it  possible. 

The  multitude  of  molar  and  chemical  motions  in  the  body 
produce  a  great  number  of  vibratory  waves  in  all  tissues. 
Differences  of  temperature  between  parts  induce  circulations  of 
heat  waves.  Differences  in  acidity  and  alkalinity  with  osmosis 
doubtless  induce  electrical  changes,  but  none  of  these  move- 
ments can  be  said  to  be  the  nervous  force.  If  we  consider  the 
nerve  elements  as  unstable  and  readily  stimulated  into  activity, 
we  cannot  ignore  the  myriad  stimuli  of  every  movement  of 
life,  awake  or  asleep. 

It  may  be  granted  that  electricity  is  one  of  the  energies  un- 
der consideration,  within  definite  limits,  as  is  the  case  with 
varying  degrees  of  heat,  with  which  the  body  in  general  and 
nerve  elements  have  established  adjusted  relations ;  and  before 


CLEVENGER — Physiology  and  Psychology.  1 2  3 

proceeding  further,  it  would  be  well  to  examine  this  perpetu- 
ally recurring  matter  of  adjustment  and  readjustment. 

We  experience  impressions,  sensations,  resolvable  into  vibra- 
tions, which  are  novel  and  provoke  reflex  or  other  motions. 
Often  repeated,  these  vibrations  cease  to  produce  the  first  ef- 
fect, "we  grow  accustomed  to  them"  suffices  generally  as  an 
explanation,  but  to  the  physiologist  that  should  be  no  explana- 
tion. The  only  inference  to  be  made  from  analogy  is  that  in 
this  failure  of  repeated  stimuli  to  produce  a  repetition  of  the 
effect,  a  readjustment  on  a  physical  basis  has  been  made.  A 
change  in  the  arrangements  of  the  molecules  which  were  at 
first  influenced  has  been  effected.  The  irritation  can  be  made 
to  induce  its  first  effect,  but  a  diffusion  of  the  vibration  into 
other  and  more  general  channels  has  evidently  occurred.  A 
change  of  plane  is  made,  and  nothing  but  a  rearrangement 
of  the  tissue  over  which  these  impulses  pass  can  explain  this 
adaptability  of  the  organism  to  changes  in  environment 

Under  repeated  strains,  muscles  visibly  adapt  themselves  to 
new  demands  by  growth.  The  nerves  are  no  exception  to  the 
rule  of  tissue-increase  through  exercise,  but  it  would  be  a 
narrow  view  to  assign  growth  of  nerves  as  the  only  means  of 
adaptability,  for  demonstrably  induration  of  other  parts  and 
diversion  of  impulses  into  diffused  channels  operate  toward 
the  same  end. 

The  physical  basis  of  readjustment  which  enables  the  miller 
to  sleep  undisturbed  by  the  noise  of  his  machinery  are  of  this 
complex  nature;  readjustment  of  many  tissues  stimulated  to 
simultaneous  growth  or  other  change,  as  the  tympanic  mem- 
brane changes,  the  tensor  tympani  relaxation  and  alteration  in 
blood-vessels.  This  is  more  apparent  in  the  artillerist  and 
boiler-maker,  whose  readjustment  entails  obtuseness  to  other 
and  ordinary  vibratory  influences.  The  rustic  is  excited  by 


1 24  CLEVENGER — Physiology  and  Psychology. 

the  confused  noises  which  the  city-dweller  does  not  notice, 
and  the  latter  feels  oppressed  by  too  long  a  continuance  of  the 
quietude  to  which  the  former  is  adapted.  It  is  safe  to  infer 
that  no  two  nervous  organizations  are  precisely  alike,  and  that 
ranges  of  difference  exist  in  the  same  species,  even  rendering 
brains  unlike  in  minute  distributions  and  texture,  when  they 
may  present  the  same  gross  morphological  appearances. 

The  general  molecular  changes  which  normally  go  on  in 
the  nerves  are  readjusted  to  an  irritative  influence,  and  discord- 
ances are  inevitable ;  a  slight  noise  or  jar  suffices  to  induce 
reflexes  which  were  before  unexperienced,  and  this  indicates, 
in  common  with  many  other  phenomena,  that  interruptions  to 
the  ordinary  vibrations  afford  the  basis  of  reflexes  and  sen- 
sations. 

An  excellent  illustration  of  my  interruption  idea  is  one 
afforded  by  respiration,  which  we  do  not  ordinarily  feel  or  of 
which  we  are  unconscious.  The  neural  changes  are  constant, 
regular,  rhythmical,  but  when  a  change  of  plane,  such  as  rela- 
tive increase  or  decrease  of  sensation  or  motion  in  other  parts, 
or  diffusion,  or  a  shock  of  any  kind  interrupts  the  motions  of 
the  heart  or  lungs,  forthwith  sensation  is  evoked,  and  the  change 
is  realized  or  felt. 

Both  the  telephonic  and  telegraphic  workings  afford  analo- 
gies. The  wires  are  traversed  by  molecular  vibrations  which 
exert  no  influence  over  the  relay  armatures  and  sensitive  diaph- 
ragms at  the  stations,  but  interruptions  to  the  passage  of  these 
molecular  movements  instantly  become  apparent  in  the  terminal 
apparatus.  Such  interruptions  may  be  effected  by  solution  of 
continuity,  increase  or  decrease  of  current  temperature,  or 
hygrometric  variations,  etc. 

The  nervous  system,  as  well  as  the  organism  itself,  is  being 
perpetually  readjusted  to  its  environment,  and  no  sooner  is  one 


C LEVENGER — Physiology  and  Psychology.  1 2  5 

plane  reached  than  alterations  occur  which  may  act  as  stimuli, 
but  cease  to  so  act.  It  is  only  through  alterations  of  adjustment 
that  impressions  are  possible.  These  plane  alterations  are,  of 
course,  limited  by  chemical  possibilities  related  to  the  integrity 
of  the  tissues. 

The  following  matters  bear  upon  this  change  of  plane : 

Muscles  which  by  degeneration  have  lost  their  nervous  sup- 
ply are  more  responsive  to  the  constant  current  than  to  induc- 
tion shocks.  Thus  the  condition  of  nerves  in  cases  of  paraly- 
sis may  be  tested. 

Nerves  suddenly  heated  or  cooled  induce  muscular  contrac- 
tions, but  not  when  application  is  gradual. 

Moderate  warmth,  45°  C.,  in  frog,  favors  nerve  and  muscle 
activity. 

Cold  at  o°  C.  diminishes  the  nerve  force  from  28  m.  to  I  m. 
per  sec. 

"  Personal  equation  "  shows  the  varying  sensibility  of  indi- 
viduals and  between  them. 

Helmholz  fixes  the  rhythmical  discharges  over  motor  nerves 
to  contract  muscle  at  1 8  to  20  in  most  animals,  and  16  to  1 8 
per  sec.  in  frogs.  Loven  found  these  discharges  to  be  12  to 
13  per  second  in  a  man's  arm. 

The  law  of  contractions,  analectrotonus  and  katalectroto- 
nus  are  interpretable  as  increase  from  low  to  normal,  or  from 
normal  to  high  planes.  Ritter's  "  making  and  breaking  teta- 
nus," shows  how  convulsions  originate  in  heightened  or  low- 
ered vital  activities. 

All  show  variability  of  nerve  vibrations  within  a  range. 
"  Regarding  sensation  as  the  sum  of  a  series  of  increments  of 
sensation  corresponding  to  increments  of  stimulus,  Fechner 
adopted  the  mathematical  operation  of  integration,  and  con- 
cluded that  sensations  increase,  not  in  proportion  to  the 
strength  of  the  stimulus,  but  to  the  logarithm  of  the  strength 
of  the  stimulus."* 

*Ross :     The  Diseases  of  the  Nervous  System,  Vol.  I.,  p.  83. 


1 26  CLEVENGER — Physiology  and  Psychology. 

A  change  of  plane  changes  effect  of  stimulus.  Hyperaesthe- 
sia  is  an  exalted  plane,  anaesthesia  a  depressed  plane. 

Adding  algebraically  stimulation  to  the  planes  affords  good 
numerical  results ;  thus,  let  the  normal  plane  equal  I ,  the  hy- 
peraesthetic  2,  then  a  normal  stimulus  of  I  added  to  normal 
plane  equals  the  ordinary  reflex  2— hyperaesthetic  plane ;  but 
i-|-2:=3=pain,  which  is  an  accompaniment  of  all  transgres- 
sions of  usual  limits. 

Some  partially  deaf  persons  hear  best  amidst  great  noise. 

The  law  of  relativity  includes  the  change  of  plane  consider- 
ation. This  law,  of  such  universal  application,  is  well  dis- 
cussed by  Bain*. 

He  shows  that  it  must  be  perpetually  kept  in  view,  in  dis- 
cussing the  emotions,  that  the  measure  of  a  feeling  is  the 
measure  of  a  transition. 

Pain  and  pleasure  are  purely  relative. 

Change  is  necessary  to  feeling. 

We  are  unconscious  of  unremitted  impressions. 

The  degree  of  feeling  is  proportioned  to  the  change. 

Abruptness  or  suddenness  of  transition  is  one  mode  of  en- 
hancing the  effect. 

Most  air-breathing  animals  are  insensible  of  the  pleasure  of 
a  transition  from  confined  to  pure  air,  as  they  are  not  so  apt  to 
experience  it  as  man  is. 

Fishes,  in  tropical  seas,  are  accustomed  to  uniformity  of 
warmth.  Never  to  feel  cold  is  never  to  feel  heat.  Hence  we 
are  unconscious  of  what  is  not  felt. 

Sightless  animals  have  no  sense  of  darkness  as  we  under-, 
stand  it. 

Pleasures  and  pains  often  depend  upon  the  one  preceding 
the  other. 

Many  pleasures  only  become  such  by  their  cessation. 

Any  excessive  indulgence  loses  its  zest. 

Novelty  is  often  pleasureable,  and  first  experiences  are  most 
acute,  as  in  puberty,  and  when  traveling,  learning,  etc. 

*Bain:     The  Emotions  and  the  Will,  p.  57  et  seq. 


CLEVENGER — Physiology  and  Psychology.  127 

The  longer  the  remission,  the  greater  the  stir  or  shock  of 
renewal. 

After  a  long  privation,  a  pleasure  may  regain  very  nearly  its 
pristine  charm. 

The  perfection  of  enjoyment  in  anything  is  a  mean  between 
the  repetition  that  makes  the  pleasure  stale  and  the  privation 
that  leaves  an  aching  void. 

The  serenity  of  the  man  of  business  under  shocks  and  vicis- 
situdes, opposition  and  abuse,  is,  in  part,  though  not  entirely, 
due  to  their  frequency. 

Case-hardening  through  familiarity  with  suffering  is  inevi- 
table. 

Ennui  is  the  feeling  during  removal  from  usual  variety  of 
pleasures. 

Monotony  and  painful  sensibility  succeed  exhaustion  of  or- 
gans after  stimulation. 

Happiness  depends  upon  rotation  of  familiar  pleasures. 

Established  nerve  impulses  cease  to  affect,  but  interruptions 
to  them  are  appreciated. 

The  law  of  diffusion  Darwin  amplifies  in  his  Expression  of 
the  Emotions  in  Man  and  Animals,  and  Bain  regards  it  as  car- 
rying with  it  the  law  of  relativity. 

According  as  an  impression  is  accompanied  with  feeling,  the 
aroused  currents  diffuse  themselves  freely  over  the  brain,  lead- 
ing to  the  general  agitation  of  the  moving  organs,  as  well  as 
affecting  the  viscera. 

The  organs  prominently  affected  by  diffusion  of  nerve  in- 
fluence are  the  members,  especially  facial  features,  ears  in 
animals,  next  the  viscera. 

Pain  may  be  suppressed  by  excitement. 

The  senses  are  correlated  so  that  one  feeling  must  predominate 
at  a  time.  The  eyes,  ears,  and  hands  cannot  minister  to  three 
different  feelings  at  the  same  time.  Frequently  a  shock  of 
feeling  will  stop  a  walk. 

No  emotion  but  that  it  has  outward  display,  if  intense 
enough. 


128  CLEVENGER — Physiology  and  Psychology. 

When  feeling  is  weak,  expression  is  weak. 

Education  restricts  impulses  to  definite  channels.  The  man 
no  longer  sticks  out  his  tongue,  as  the  child  does,  when  he 
writes. 

To  recapitulate : 

Eminently  contractile  tissues  (muscles)  and  eminently  irrita- 
ble or  mobile  tissue  (ganglionary  gray)  underwent  differential 
development  and  separation.  Eminently  sensitive  organs  were 
subsequently  developed  from  indifferent  substances  (mainly 
pigment)  in  the  ectoderm. 

These  three  groups  were  united  internuncially. 

All  developed  from  the  primitive  fibrils  arranging  themselves 
in  lines  of  least  resistance ;  such  fibrils  as  conduced  most  to 
useful  action  being  perpetuated  and  developed  through  use, 
the  remainder  of  the  network  remaining  undeveloped.  In  this 
way,  definite  nerve  tracts  arose,  grew,  and  were  inherited,  un- 
dergoing subsequent  development  and  alteration  through  the 
operation  of  the  same  laws  which  originally  called  them  into 
existence. 

Nerves  undergo  mainly  quantitative  development,  L  e.y  sizes 
and  densities  of  axis  cylinders  may  differ,  but  nerve  tracts  are 
essentially  alike. 

End  organs  differ  qualitatively. 

Increase  of  connections  is  followed  by  increase  of  function 
differentiation ;  and  where  commissural  union  is  greatest  in 
brains,  intelligence  is  greatest  (Spitzka*). 

Sizes  of  axis  cylinders  and  nerve  cells  are  regulated  by  use. 

Time  is  required  in  all  nerve  phenomena. 

Nutrition,  repair  of  waste,  the  assimilation  of  protagonous 
material  from  the  blood,  as  well  as  oxygen  therefrom,  is  a 
prime  essential  to  nerve-action.  Exhaustion  for  shorter  or 

*  Architecture  and  Mechanism  of  the  Human  Biaia 


CLEVENGER — Physiology  and  Psychology.  1 29 

longer  time  follows  action,  denoting  something  consumed,  and 
gray  matter  is  the  place  where  the  greatest  consumption  of 
material  occurs. 

The  necessity  for  the  absence  of  much  pressure  points  to  a 
mechanical  factor  in  nerve-mobility,  as  well  as  a  chemical ;  a 
certain  freedom  for  molar  motion  is  a  requisite. 

The  increased  amount  of  force  put  forth  by  an  animal  in- 
creases nerve  size. 

The  multiplicity  of  motions  increasing,  increases  size  of 
nervous  system. 

Both  quantity  and  multiplicity  of  motion  increase  it  to  the 
greatest  extent. 

Nerve  fibrils  are  in  constant  motion,  molar  or  molecular,  or 
both,  during  life,  independently  of  the  atomic  and  molecular 
motions  involved  in  the  disintegration  and  reintegration  of  all 
physiological  structures. 

Indifferent  tissues  may  and  do  convey  vibrations,  and,  when 
passing  centripetally  over  other  than  nerves,  produce  central 
nerve  action,  though  the  cushioning  of  the  cerebro-spinal  fluid 
minimizes  this.  Nevertheless,  extraneous  vibrations,  such  as 
shocks  and  jars,  are  apprehended  centrally;  any  way  in  which 
such  jars  could  affect  the  centers,  would  become  the  mode  in 
which  such  jars  are  cognized.  A  fall  upon  the  head  inducing 
flashes  of  light  and  tinnitus  aurium  show,  in  common  with 
other  matters,  that  molar  motions  of  the  coarsest  kind  can  in- 
duce the  molecular  movements  of  sight  and  auditory  centers. 
The  shiver  produced  by  unpleasant  vibrations  experienced  in 
riding  over  badly-equipped  railroads,  or  in  some  by  passing 
the  hand  over  velvet,  are  other  instances  of  the  interruptions  to 
normal  waves  sufficient  to  provoke  diffused  reflexes  being 
generated  by  ordinary  molar  motions.  Even  the  horripilation 
felt  in  handling  a  peach  is  of  a  mechanical  nature. 


130  CLEVENGER — Pkysiology  and  Psychology. 

All  nerves  convert  their  initial  impacts  into  terms  of  general 
sensation,  as  evidenced  by  homogeneity  of  nerve-structure. 

Interruptions  to  and  changes  of  normal  nerve-currents  con- 
stitute stimuli. 

Adjustment  and  readjustment  of  the  nervous  system  is  in- 
cessant and  causes  change  of  plane  of  nervous  action  in  vary- 
ing degrees. 

Change  of  plane  changes  effects  of  stimuli. 

Fechner's  law  of  stimuli  increase  is  involved  in  the  forego- 
ing considerations  as  a  sub-consideration. 

The  laws  of  relativity  and  diffusion  are  all  important  in  con- 
nection with  nervous  and  mental  operations. 

These  matters  being  conceded,  the  impossibility  of  assigning 
any  special  rate  of  vibration  or  wave  length  for  normal  nerve 
impulse  can  be  seen.  Only  the  broadest  generalizations  are 
admissible,  such  as  warrant  the  belief  that  nerve  action  is  more 
rapid  in  birds  than  in  mammals,  swifter  in  the  latter  than  in  rep- 
tiles, and  the  interruptions  to  nerve  action  would  produce 
quicker  reflexes  in  such  animals  as  possessed  the  quickest 
nerve  currents.  The  existence  of  constant  currents  is  a  nec- 
essary outcome  of  the  acknowledgment  that  nerve  molecules 
move  at  all,  and  that  there  are  ever  present  sources  of  stimula- 
tion. 

Helmholz  assigns  twenty-eight  m.  per  second  as  the  rate  in 
frogs,  thirty-three  m.  in  man.  Foster  *  adopts  the  latter  rate 
for  both  sensory  and  motor  activity,  believing  himself  justified 
in  so  doing  through  inability  to  otherwise  reconcile  the  various 
discrepancies  of  investigators.  The  normal  current  would 
vary  in  health  and  disease ;  probably  the  most  accurate  figure 
for  the  rate  could  be  obtained  by  using  the  circulatory  as  a 
multiplier.  The  pulse-wave  velocity  of  between  nine  and  ten 


•*  Text- Book  of  Physiology,  Reichert's- Foster. 


CLEVENGER — Physiology  and  Psychology.  131 

m.  per  second  (Weber)  could  be  taken  as  a  factor,  though  the 
widely-varying  velocity  of  the  blood  itself  in  different  chan- 
nels and  its  differences  of  pressure  are  potent  as  increments  of 
neural  velocities  and  are  results  often  of  such  velocities. 

Adjustment  has  taken  place  with  relation  to  the  circulation 
so  that  it  is  seldom  felt  save  in  overplus  rapidity  and  in  the 
states  which  produce  tinnitus  aurium. 

The  relative  swiftness  of  pulse  and  nerve  waves  stand  thus 
as  one  to  three  or  thereabouts,  often  rising  and  falling  together 
or  reacting  upon  each  other. 

Helmholz'  33m.  per  second  suffices  to  base  calculations  upon 
in  all  nerves. 

Schmidt  *  measures  fibrillae  of  neuroglia  at  T£TT  to  -sfa  mm.  in 
diameter,  and  axis  cylinders  of  adjacent  cell  processes  at  from 
2^0  to  ^-5  mm. 

Thirty-three  m.  per  sec.  with  axis  cylinder  composed  of 
globules  .01  to  .001  mm.  in  diameter  affords  an  impact  or  ex- 
plosion between  globules  at  the  rate  of  from  33xio5  to  33xio6. 
Let  us  adopt  io7as  the  usual  rate,  for  convenience  of  calcula- 
tion, that  is,  as  the  rate  common  to  some  nerves  under  some 
circumstances. 

But  the  actual  rates  of  nerve  molecular  motion  are  of  as  little 
consequence  as,  those  of  any  other  chemical  change.  What 
value  could  attach  to  a  knowledge  of  the  rapidity  of  disinte- 
gration and  reintegration  of  the  water  molecules  going  on  in 
a  jar  of  battery  in  electrical  generation  upon  Grotthus'  hy- 
pothesis ? 

Haycraft,f  in  an  essay  upon  the  limitations  of  time  of  con- 
scious sensation,  states  that : 

If  any  sensory  surface  be  stimulated  for  a  given  period,  a 

*  Journal  of  Nervous  and  Mental  Disease,  January,  1879. 
f  Brain,  April,  1884,  p.  141. 


132  CLEVENGER — Physiology  and  Psychology. 

sensation  will  be  produced  which  will  not  exactly  correspond 
with  this  stimulation  in  point  of  time. 

The  sensation  will  be  produced  a  certain  interval  after  the 
first  movement  of  application  of  the  stimulus.  It  follows  from 
this  that  two  stimuli  following  one  another  sufficiently  rapidly 
will  give  rise  to  a  single  sensation.  The  correspondence  in  time 
between  the  stimulus  and  sensation  varies  in  the  case  of  the 
different  senses. 

Tactile  impressions  applied  slowly  (one  to  forty  per  second) 
give  rise  to  distinct  and  separate  feeling.  More  rapid  stim- 
uli are  fused  and  a  feeling  or  sensation  of  "roughness"  is 
produced. 

If  the  impacts  follow  faster  than  fourteen  hundred  per  sec- 
ond, the  sense  of  "  roughness  "  disappears  and  a  sensation  of 
single  impact  is  produced.  Tickling  is  produced  whether  an 
impact  stimulates  a  number  of  sensory  areas  one  after  the 
other,  as  in  drawing  a  feather  over  the  skin,  or  if  impacts  fol- 
lows one  another  on  the  same  sensory  area ;  for  impacts  of 
fifty  to  fourteen  hundred  per  second,  if  applied  to  the  same 
sensory  area,  produce  "roughness"  if  forcible  enough,  but 
when  lightly  applied  they  produce  "  tickling." 

Different  areas  of  the  skin  vary  in  sensibility.  Sensations 
of  heat  and  cold  vary  in  times  of  appreciation.  Haycraft  holds 
that  the  differences  in  the  exact  limits  of  the  feelings  seen  in 
the  different  sensations  are  not  due  to  any  difference  in  the 
centrally  produced  feelings,  but  to  the  differences  seen  in  the 
translation  of  the  external  energy  into  nerve  Energy  through 
the  end  organs. 

In  the  sensations  of  sound  and  light,  as  well  as  in  the  tactile 
sensibility,  when  stimuli  are  repeated  more  and  more  rapidly, 
a  period  preceding  complete  fusion  is  reached  when  the  sen- 
sation produced  is  disagreeable  in  its  nature.  In  the  case  of 
sound,  the  irritation  is  produced  by  beats ;  the  cause  of  "  dis- 
sonance "  in  music  is  due  to  recurring  stimuli  not  to  be  sepa- 
rated in  consciousness,  and  yet  not  rapid  enough  to  give  rise 
to  a  simple  sensation  of  sound. 

The  flickering  of  a  flame  is  irritating  in  its  nature,  and  tick- 


CLEVENGER — Physiology  and  Psychology.  133 

ling  in  the  case  of  tactile  sensibility  may  give  rise  to  excrucia- 
ting agony.  We  may  compare,  therefore,  roughness  or  tick- 
ling, tactile  sensations,  to  dissonance  in  music.  Bloch*  finds 
tactile  sensibility  from  finger  of  hand  took  ji  second  longer 
than  by  auditory  apparatus.  Vision  is  most  rapid,  next  sound, 
which  is  yV  second  longer  than  visual  transmission,  and  tac- 
tile sensation  is  TT  second  longer  in  transmissions  than  vision. 

If  nerves  conveyed  physical  forces  per  se,  there  would  be  no 
use  of  end  organs.  It  is  in  these  peripherally  located  organs 
that  translation  of  impacts  occurs  into  terms  of  interruptions  of 
previously  existent  vibrations. 

Stimuli  added  to  the  ever-present  stimuli  which  induces  the 
normal  can  but  change  the  rate  of  speed,  but  when  once 
changed  and  persisting,  it  becomes  a  change  of  plane  and 
ceases  to  be  a  sensation.  It  is,  therefore,  the  rise  and  fall  of 
rapidity  which  is  appreciated,  and  the  rapidity  of  this  rise  and 
fall  is  the  thing  appreciated,  for  slowly  induced  changes  we 
know  are  unfelt. 

We  cannot  multiply  the  number  of  vibrations  causing  the 
sensation  into  the  pre-existent  waves,  for  the  reason  that  the 
new  effects  of  stimulation,  if  prolonged,  become  blended  with 
the  previous  normal.  An  acceleration  of  the  normal  must  be 
granted  as  an  effect  of  all  stimulation,  but  continued  stimula- 
tion ceases  to  accelerate,  and  a  plane  near  the  former  normal 
is  reached  in  longer  or  shorter  time.  Thus  the  "  palling  "  or 
cloying  of  senses  occurs. 

Sensation,  so  far  as  movements  among  the  nerve  elements 
is  concerned,  is  accompanied  by  two  conditions,  the  temporary 
acceleration  of  the  normal,  and  intervals  between  impacts  of 
acceleration.  The  normal  can,  by  exhaustion,  drop  below  its 
usual  plane,  so  far  as  to,  though  relatively,  cause  the  sense  of 
an  interval  between  impacts. 

*Gazette  des  hCpitaux,  No.  128,  1883. 


1 34  CLEVENGER — Physiology  and  Psychology. 

Conceive  io7  the  nerve  normal.  A  single  impact  in  a  second 
raises  this.  The  instant  of  contact,  the  acceleration  and  the 
cessation  or  drop  to  normal,  which  may  not  be  simultaneous 
with  duration  of  impact,  constitute  the  impression.  The  prob- 
lem would  be  simpler  if  simultaneity  existed,  but  as  the  dura- 
tion of  an  impression  outlives  the  impact,  it  must  be  duly  con- 
sidered. 

Tactile  fusion  occurs  with  fifty  and  with  fourteen  hundred 
impacts  per  second. 

Ocular  sensations,  repeated  ten  times  a  second,  fuse. 

One  hundred  and  thirty -two  dissonant  "beats"  of  tuning 
forks  fuse. 

Forty  auditory  vibrations  per  second  last  TT  second,  forty 
thousand  last  ?ihr  second. 

Residual  optic  sensation  for  light  of  moderate  intensity  is 
??  second.  Red,  violet,  and  green  last  in  the  order  named. 

The  interval  between  optic  stimuli  varies  according  to  the 
light  intensity,  being  shorter  with  stronger  light.  Faint  light 
has  an  interval  of  about  TO  second,  strong  light  TO-  second  to 
FO-  second.  Though  the  sensation  is  longer  with  the  stronger 
light,  the  decline  begins  earlier,  and  successive  sensations  of 
bright  light  are  fused  with  greater  difficulty.  The  interval  at 
which  fusion  occurs  is  shortest  with  yellow,  intermediate  with 
red,  and  longest  with  blue. 

The  duration  of  a  stimulus  necessary  to  affect  the  retina  is 
exceedingly  short,  as  when  the  electric  spark  causes  sensation 
of  light. 

The  smallest  difference  of  light  which  we  can  appreciate  is 
about  r-o-<y  of  the  total  luminosity  used.  The  same  law  holds 
good  with  the  other  senses.  The  smallest  difference  we  can 
detect  in  length  between  two  lines  is  the  same  fraction  of  feet 
or  inches,  in  lines  feet  or  inches  in  length.  Weber's  law  is, 
that  appreciation  of  stimulus  increase  varies  in  proportion  to 
the  whole  stimulus,  and  it  fails  where  the  stimulus  is  very 
small  or  very  great.  Fechner's  law  is  that  the  "  sensation  varies 
as  the  logarithm  of  the  stimulus." 


CLEVENGER — Physiology  and  Psychology.  135 

According  to  the  obtuseness  or  extreme  sensitiveness  of  the 
end  organ,  so  will  the  duration  of  the  impression  be  shorter 
or  longer. 

For  the  same  organ  slow  vibrations  are  felt  longer  than 
quick  vibrations. 

For  the  same  organ  intensity  of  impression  lengthens  the 
duration.  But  the  rapidity  of  conduction  is  a  different  matter. 
This  has  been  worked  out  through  Exner's  "  reaction  periods," 
but  we  cannot  use  the  tables,  for  the  time  of  conversion  of 
impressions  into  nerve  waves  and  motor  effects  are  not  sepa- 
rated. To  determine  differences  between  senses  it  might  an- 
swer, but  not  between  muscle  and  nerve  action. 

The  fact,  however,  that  this  action  is  accelerated  in  hyper- 
aesthesia,  and  retarded  in  anaesthesia,  bears  upon  the  change 

4 

of  plane  theory. 

There  is  obviously  less  resistance  to  the  tactile  movements 
in  nerves  admitting  full  appreciation  of  forty  impacts  per  sec- 
ond as  separate  sensations,  and  imperfect  appreciation  of  these 
to  fourteen  hundred  per  second  as  "  roughness,"  than  in  the 
optic  nerve  movements,  which  fuse  impressions  of  ten  per 
second. 

The  question  may  well  be  asked,  Is  this  due  to  continuous 
peripheral  action  or  to  the  central  duration  of  the  impression  ? 
"  Dilemma"  times  and  durations  measured  on  nerves  separated 
from  terminals,  suffice  to  show  it  to  be  largely  non-peripheral, 
though  there  is  a  mixture  not  eliminated. 

In  an  endeavor  to  trace  the  evolutionary  aspects  of  the  dif- 
ferent senses,  it  is  to  be  remembered  that  the  tactile  sense 
itself  has  undergone  development,  and  that  the  primitive  sensi- 
bility is  far  more  obtuse.  The  greater  duration  of  an  impres- 
sion is,  in  some  respects,  a  measure  of  its  higher  development. 


1 36  CLEVENGER — Physiology  and  Psychology. 

Though  both  tactile  and  auditory  are  closely  related,  the 
manner  in  which  the  receptive  organs  are  impressed  in  both 
cases  differ.  The  cuticle  is  directly  touched  with  a  compara- 
tively hard  substance  in  one  instance,  and  in  the  other  an 
elastic  medium,  the  air,  conveys  its  pulsations  to  the  tym- 
panum, and  modifications  of  these  waves  are  undergone  before 
the  auditory  nerve  is  affected. 

Mayer's  researches  on  the  male  mosquito  antennae  prove  in 
that  case  that  the  aerial  pulses  affect  the  fibrils  at  right  angles 
to  the  antennae  ;  the  latter  conveys  the  resulting  waves  inward, 
but  there  is  a  multiplicity  of  arrangements  for  effecting  audi- 
tory appreciation  between  different  invertebrates.  The  ver- 
tebrate auditory  apparatus  has  a  decidedly  mechanical  structure. 

The  ability  to  distinguish  separate  impacts  in  time  is  one 
thing,  and  the  ability  to  distinguish  series  of  vibrations  apart 
from  each  other  is  another.  The  first  is  of  a  molar  nature  or 
moleculo-molar,  the  second  is  molecular  and  consists  of  chem- 
cal  disruptions  comparable  to  the  explosion  of  the  nitrite  when 
the  musical  note  to  which  it  is  susceptible  tears  its  molecules 
apart. 

Helmholz  *  says  :  "As  the  difficulty  of  making  a  trill  in  the 
bass  is  the  same  in  all  musical  instruments,  the  vibrations  of 
the  mobile  parts  of  the  ear  for  bass  are  not  damped  enough  to 
prevent  two  sounds  succeeding  each  other  so  rapidly  without 
blending.  There,  hence,  must  be  in  the  ear  different  parts 
which  are  set  in  vibrations  by  sounds  of  different  heights,  and 
which  give  the  sensations  of  these  sounds. 

"  For  40  vibrations  per  second,  a  residual  sensation  lasting 
TI  sec.  For  40,000  vibrations  per  second,  a  residual  sensation 
lasting  3S7  sec.  Thus  the  residual  sensation  of  30  vibrations 
per  sec.  should  last  fV  sec.,  for  they  follow  at  -fa  sec.  intervals. 
Why  do  they  blend? 

*  Tonempfindungen,  p.  215. 


CLEVENGER — Physiology  and  Psychology.  137 

"  Do  not  these  distinct  impulses  fall  on  the  ear  in  TG  sec.  ?  Co- 
vibrating  bodies  in  the  ear  tuned  to  vibrations  below  40  per 
second  do  not  exist.  The  ear  vibrates  en  masse,  and  the  dura- 
tion of  these  oscillations  of  the  ear  as  a  whole  are  far  too 
short  to  remain  the  -fa  sec." 

Some  of  the  agencies  to  produce  vibratile  motion  are  com- 
paratively coarse,  such  as  otoliths,  while  the  tactile  corpus- 
cles receive  their  impacts  direct,  and  their  wave  interruptions 
appear  to  be  of  a  simpler  nature ;  the  auditory  apparatus  is 
elaborated  to  converge  the  diffused  sound  waves,  and  convert 
them  into  vibratile  motions  of  lesser  terms.  The  lower  series 
of  notes  act  as  tactile  impressions  to  the  ear  and  induce  molec- 
ulo-molar  changes,  the  higher  up  to  40,000  (the  range  being 
only  to  16,000  in  most  persons)  waves  per  second  produce  such 
neural  motions  as  are  closely  allied  to  the  1,400  per  second 
"  roughness  "  discrimination  of  the  tactile  sense  wherein  the 
molar  motion  is  a  minor  product  and  the  molecular  the  major 
one. 

The  moleculo-molar  rapidly  fades  into  the  molecular  as 
40,000  is  approached  in  hearing  and  1,400  in  feeling.  The 
disagreeable  feeling  Haycraft  notes  as  preceding  fusion  is  the 
dissonance  of  erratic  nerve  action.  The  capacity  of  the  nerve 
for  certain  rates  of  waves  is  transcended,  and  correlatively 
painful  mental  feelings  occur  during  doubting  or  constraint. 
Higher  than  40,000  auditory  waves  are  not  appreciated,  because 
there  is  no  end  organ  in  man  rendering  him  susceptible  to 
them. 

The  opacity  of  nerve  substance  precludes  the  possibility  of 
light  vibrations  passing  to  the  cortex.  Heat  appreciation  must 
be  translated  into  lower  terms,  for  high  heat  molecular  move- 
ments are  disintegrative.  We  are  forced  to  the  conclusion  that 
neural  vibrations  are  normally  higher  than  sound,  over  40,000, 
and  much  lower  than  heat  vibrations  of  the  ultra  red  ray. 


138  CLEVENGER — Physiology  and  Psychology. 

The  disintegration  of  the  visual  purple,  causing  interruptions 
of  optic  wave-lengths,  seems  the  most  rational  explanation  of 
sight.  Rhodopsin  absorbs  all  rays,  and  it  is  fair  to  presume 
that  upon  its  disintegrative  times  will  depend  the  color  of  the 
light  perceived. 

Gamgee  *  dwells  upon  the  bleaching  phenomena,  and  cites 
many  facts  which  could  be  usefully  considered  in  elaboration 
of  a  chemical  interference  theory.  We  have  room  for  a  few 
only. 

The  order  of  bleaching  is  yellowish-green,  green,  blue, 
greenish-yellow,  yellow,  violet,  orange,  red. 

According  to  Boll,  light  perpetually  destroys  the  retinal 
color,  and  darkness  regenerates  it.  Thus  in  the  space  of  a 
wink  regeneration  occurs,  and  light,  acting  upon  many  points, 
affords  time  for  regeneration  of  points  acted  upon.  Mayer  t 
appropriately  remarks :  "  May  not  research  in  this  direction  be 
guided  by  the  hypothesis  that  the  molecular  constitution  of 
the  retinal  rods  and  cones  is  such  that  their  molecules  are 
severally  tuned  to  vibrations  corresponding  to  the  red,  green, 
and  violet?  This  would  lead  us  to  look  for  effects  of  actinism 
on  the  retina,  as  showing  the  link  existing  between  the  trans- 
mitting and  sensory  functions  of  the  eye.  Do  not  the  facts  of 
the  known  persistence  of  chemical  action,  after  it  has  once  been 
initiated,  and  the  time  which  would  be  required  for  the  retinal 
molecules  to  re-combine  or  re-arrange  themselves  after  the 
ethereal  vibrations  had  ceased,  comport  with  the  known  dura- 
tions of  the  residual  visual  sensations,  and  with  the  main  facts 
of  physiological  optics,  better  than  the  hypothesis  that  masses 
of  the  retinal  elements  are  set  in  vibration,  rather  than  their 
molecules?" 

Actinism  is  often  erroneously  used  in  the  sense  of  being  the 
only  chemical  force.  Many  forces  produce  chemical  effects, 
such  as  sound,  heat,  electricity,  as  well  as  light,  but  actinism  is 

*  Physiological  Chemistry  of  the  Animal  Body,  p.  465. 

f  Researches  in  Acoustics,  Am.  Jour.  Arts  and  Sci.,  1874,  p.  251. 


CLEVENGER — Physiology  and  Psychology.  \  39 

the  light  chemical  force,  and  abounds  in  the  violet  ray  and  be- 
yond, though  inherent  in  all  rays.  The  molecular  force  men- 
tioned herein  as  constituting  the  actinic  is  of  lesser  wave 
length  than  any  light  ray.  White  light  appears  to  me  to  be 
the  resultant  of  all  rays  through  destructive  impacts,  while 
purple  absorbs  all  rays.  The  law  of  relativity  causes  the  eye 
to  accept  as  white  light  any  light  prevailing  if  intense  enough. 
So  the  nervous  system  growing  habituated  to  myraid  impulses, 
accepts  these  as  the  normal  ones,  and  variations  from  the  plane 
adopted  become  the  excitants.  Many  noises  to  which  the  ear 
grows  accustomed  constitute  an  analogous  datum  plane  for 
audition,  which  must  be  transcended  in  amplitude  or  wave- 
length to  stimulate  the  acoustic  apparatus. 

Color  perception  is  a  difTerentation  of  simple  perception  of 
light  and  shade,  such  as  we  have  reason  to  think  constituted 
the  rudimentary  light  perception.  The  subsequently  acquired 
media  of  the  eye  act  as  does  water  in  cutting  off  the  heat  rays, 
otherwise  heat  would  be  seen.  A  pigment  which  responded 
indifferently  well  to  light,  gave  place  to  the  visual  purple  with 
definite  actinic  attributes.  From  the  great  rapidity  of  all  light, 
there  must  be  an  intensification  of  pre-existing  nerve  vibra- 
tions. In  the  dark,  the  normal  vibrations  occur  over  the  optic 
nerve,  but  a  little  light  suffices  to  start  the  molecules  to  more 
rapid  interchanges  of  position.  Periods  of  vibrations,  or  times, 
constitute  pitch  in  music  and  hue  in  color.  The  amplitudes 
decide  the  intensities  of  sound  and  the  brightness  of  light. 
Hence,  in  dealing  with  stimuli,  the  height  as  well  as  length  of 
a  wave  must  be  measured. 

The  rapidity  with  which  rhodopsin  changes,  varying  in  dif- 
ferent individuals,  culminates  in  extreme  variability  in  color- 
blindness, and  the  acuteness  of  color  perception  which  accom- 
panies or  precedes  some  forms  of  insanity.  Sight  is  dependent 


140  CLEVENGER — Physiology  and  Psychology. 

upon  visual  purple  interference  or  absorption  of  rays.  Where 
the  pigment  fails  to  bleach,  or  changes  too  rapidly  or  too 
slowly,  color  aberration  would  be  inevitable. 

M.  Morren,*  referring  to  Tyndall's  Kinetic  Energy  of  Vapors 
in  Light,  says  :  "  If  a  body  forms  and  maintains  itself  in  cer- 
tain undulatory  conditions,  it  is  necessary  that  the  oscillations 
of  the  atoms  which  constitute  its  molecule  should  be  different 
from  those  of  the  medium  where  the  body  is  produced.  But 
if  the  body  is  transplanted  into  another  medium,  where  vibra- 
tions synchronous  with  those  of  its  atoms  are  produced,  the 
vibrations  of  these  last  become  more  energetic,  and  the  live 
force,  which  they  accumulate,  thus  becoming  considerable,  the 
atoms  are  thrown  to  a  distance  from  each  other  greater  than 
the  radius  of  their  sphere  of  action.  The  atomic  edifice,  pre- 
viously formed,  is  demolished,  the  atoms  preserving  their  special 
attractions  for  a  new  edifice,  possible  in  the  conditions  of  oscil- 
lation which  surround  them,  consequently  not  possessing 
longer  the  same  synchronous  oscillation  as  those  of  the  me- 
dium." 

Thus,  with  the  free  light  waves  saturating  rhodopsin  with 
wave  lengths  .0007  mm.  long,  at  the  rate  of  392  x  io12,  for 
red  light,  and  .0004  mm.  long,  with  a  rapidity  of  757  x  io12, 
for  violet  light,  retardation  of  these  times  and  elongation  of 
the  waves  takes  place,  raising  our  hypothetical  nerve-current 
from  ior  to  x,  y,  z  X  io7.  The  multipliers  can  readily  take 
the  place  of  the  three  nerves  of  the  Young-Helmholz  theory 
of  red,  green,  and  violet  light,  and  intermediate  rates  would 
account  for  the  other  colors,  the  x,  y,  z  being  molecular  modes 
possible  to  the  optic  tract  and  synchronous  movements  of  any 
two  or  all  constituting  the  composite  color  sensation. 

The  increased  rapidity  of  nerve  action,  with  increments  of 
heat,  about  I  m.  for  3°  C,  is  an  expression  of  the  physicist's 

*Comptes  Rendus,  Aug.  gth,  1869. 


CLEVENGER — Physiology  and  Psychology.  1 4 1 

observation  that  the  "  kick  "  of  a  molecule  depends  upon  its 
increase  in  temperature. 

Lockyer  compares  the  motions  of  sound  and  light  to  the 
orderly  movements  of  a  company  of  soldiers,  and  likens  the 
molecular  motions  induced  by  heat  to  the  irregular  movements 
of  a  crowd.  This  simile  may  be  carried  into  neural  vibrations, 
those  induced  by  electricity,  light,  sound,  or  tactile  impression 
being  orderly  and  definite,  while  heat  tends  to  add  to  the  in- 
stability of  the  molecule,  and  where  it  induces  movements, 
they  are  of  an  irregular  nature ;  but  these  very  irregularities 
constitute  their  mode  of  impressing  themselves  upon  the  con- 
sciousness. 

Olfaction  apparently  depends  upon  an  irregular  molecular 
motion  of  particles  impinging  upon  the  Schneiderian  mem- 
brane distribution,  odorous  substances  having  regular  orbital 
rotations  constant  for  each  substance,  aerial  interferences  mak- 
ing their  conveyance  to  the  nostril  irregular. 

Gustatory  sense,  when  separated  from  olfactory  and  tactile 
accompaniments,  evidently  stimulates  the  taste  buds  through 
solution  and  chemical  disruption,  rotations,  and  impacts. 
Above  and  below  40°  C,  taste  is  impaired,  showing  the  cir- 
cumscribed nature  o-f  this  differentiated  tactile  sense. 

Touch =   IO7X   b -(-,  Steady  pressure  to  50  and  1,400 

impacts  per  second. 

Taste =   io7x  c  -J-,  Moleculo-molar  solution  impacts. 

Smell —   io7X  d  -J-,  Molecular  rotations 

Hearing =   io7X  e -f ,  40  to   40,000   aerial    pulsations 

per  second. 
Sight =   IO7X   f  -K  Rhodopsin   bleaching  by  atomic 

vibrations  392  X  iO12to  75  7  X  IO12 

per  second. 


1 42  CLF.VENGER — Physiology  and  Psychology. 

Heat =  i o7 X  g +,  Irregular  vibrations  with  ampli- 
tudes and  lengths  increasing  I 
m.  per  3°  C.  per  second. 

The  law  of  diffusion  may  assist  in  seeking  the  values  of  a 
to  g. 

Some  effects  of  diffusion  upon  nerves  are  secondary,  such  as 
those  resulting  from  the  heart  palpitations,  tremblings,  flush- 
ings, etc.;  but  primarily  diffusion  may  increase  or  decrease 
general  sensibility,  tactile  in  production  of  formications,  gus- 
tatory sense  in  producing  taste  impressions  (occasionally  during 
fright,  anger,  or  electrical  stimulations  of  other  nerves,  showing 
close  relationship  of  taste  and  tactile),  vaso-motor  and  motor 
disturbances.  Sometimes  tinnitus  is  induced,  but  this  may  be 
secondary  from  vascular  changes.  Audition,  olfaction,  and 
sight  are  in  health  generally  beyond  the  range  of  diffusion  of 
nerve  excitement. 

For  working  purposes,  arbitrary  values  of  a  to  f  may  be 
taken  as  ranging  from  2  to  7.  Heat  having  an  altogether 
different  motion  from  the  other  forces,  g  would  have  hyper- 
neurotic  general  value  to  be  considered  apart. 

Thus  the  higher  molecular  energies,  as  electricity,  light, 
heat,  and  the  moleculo-molar  energy,  sound,  may  stimulate 
sensations  of  each  other  in  a  descending  series,  and  produce 
tactile  and  motor  phenomena,  but,  as  a  rule,  the  lower  rate  of 
vibrations  cannot  produce  the  higher,  except  in  abnormal  con- 
ditions of  the  nerves  when  hallucinations  of  the  higher  senses 
are  possible. 

This  explains  why  paraesthesiae  are  so  common  as  to  pass 
almost  unnoticed,  but  aberrations  of  the  higher  senses  denote 
profounder  disease. 

The  loss  of  taste  and  smell  are  the  most  common  affections 
of  special  sense  associated  with  anaesthesia;  loss  of  hearing  is 


CLEVENGER — Physiology  and  Psychology.  143 

less  frequent,  and  loss  of  sight  is  rare.  In  hemianaesthesia, 
taste  and  smell  are  usually  abolished  on  one  side,  but  hearing 
and  vision  are  only  diminished.* 

When  a  locomotory  organ  arose  in  metazoon  existence,  there 
was  a  concomitant  necessity  for  a  definite  amount  of  nerve 
vibrations  to  pass  to  that  organ;  otherwise  it  would  either 
not  act  or  would  react  to  all  stimuli.  Thus  a  subsequently 
acquired  organ  must  have  another  amount  of  impulse  over  its 
nerves.  These  rates  must  be  relative  to  the  plane  of  whole 
neural  activity.  Effort  means  increase  of  molecular  activity, 
and  as  weighty  organs  require  more  muscular  effort,  so  there 
cannot  fail  to  be  established  differences  between  amounts  of 
neural  vibrations  sent  to  parts  requiring  to  be  moved. 

In  telegraphic  engineering,  the  amount  of  current  evolved  is 
termed  its  quantity,  which  may  be  increased  or  diminished  by 
lessening  or  increasing  the  resistance  in  circuit  both  in  the 
generator  and  on  the  line.  The  quantity  of  electricity  which 
in  any  unit  of  time  flows  through  a  circuit  is  called  the  inten- 
sity of  the  current. 

This  intensity  is  equal  in  all  parts  of  the  circuit,  no  matter 
how  heterogeneous  the  parts  are,  and  it  is  proportional  to  the 
electro-motive  force. 

Resistance  is  inversely  proportional  to  the  intensity  of  the 
current.  From  this,  Ohm  deduced  his  celebrated  law:  "The 
intensity  of  the  current  is  equal  to  the  electro-motive  force 
divided  by  the  resistance,"  which  is  expressed  in  the  formula  : 
I— g  where  I  =  intensity,  E  =  electromotive  force,  and  R  = 
the  resistance. 

Many  telegraphic  laws  are  applicable  to  the  nervous  system. 
We  derive  four  considerations :  intensity,  quantity,  resistance, 
and  energy  (molecular).  The  differences  between  quantity 
and  intensity  may  be  apprehended  by  comparing  the  relative 
energies  of  two  rivers  flowing  five  miles  an  hour,  one  having 
*  Ross  :  The  Diseases  of  the  Nervous  System,  p.  99. 


144  CLEVENGER — Physiology  and  Psychology. 

a  width  of  a  mile,  and  the  other  of  a  few  feet.  The  inten- 
sity of  both  is  the  same,  but  the  quantity  of  the  wider  is  the 
greater.  Lessen  the  current  rapidity  in  the  first  instance  to  a 
few  feet  per  hour  and  increase  the  rapidity  of  current  in  the 
small  stream  to  fifty  miles  per  hour,  and  the  intensity  of  the 
smaller  stream  exceeds  that  of  the  larger,  while  quantities 
may  remain  alike. 

Haskins  *  defines  electro-motive  force  as  the  power  which  a 
cell  or  battery  possesses  of  causing  a  transfer  of  its  current 
from  one  place  to  another.  For  our  purposes  this  may  be 
termed  energy.  It  is  to  current  what  pressure  is  to  steam. 

This  energy  or  pressure  when  impeded  or  resisted  lessens 
the  quantity  of  the  current.  C  =  ^  may  be  substituted. 

The  quantity  of  current  over  a  nerve  may,  from  this  analogy, 
be  regulated  by  the  resistance  of  the  nerve. 

Greater  muscular  action  calling  for  greater  neural  energy, 
the  larger  the  sum  of  the  combined  cross-sections  of  the  axis 
cylinders,  the  greater  will  be  the  quantity,  the  less  will  be  the 
resistance,  and  as  C  =  —  the  lessened  resistance  of  the  larger  axis 
cylinder  admits  of  a  greater  quantity  of  molecular  movement  for 
the  same  energy  or  pressure  (rapidity  of  vibration)  than  when  tJie 
axis  cylinder  is  small. 

The  relative  total  current  force  may  rise  and  fall  with  change 
of  plane,  but,  cceteris  paribus,  the  relatively  larger-sized  motor 
nerve  of  the  same  level  offers  a  better  avenue  for  quantity  than 
the  sensory  nerve.  The  tensions  of  differently  sized  wires 
may  be  paralleled  by  differently  sized  nerves  in  apposition. 
With  the  greater  resistance  of  the  smaller-sized  sensory  nerve, 
the  tension  would  be  great,  and  the  current  would  be  extremely 
easy  thence  to  the  larger  motor  fibers. 

*  The  Galvanometer  and  Its  Uses,  p;  8. 


CLEVENGER — Physiology  and  Psychology.  145 

When  the  sum  of  the  centrally  produced  vibrations  are  suffi- 
cient in  energy  or  pressure  to  overcome  the  resistance  of  a  motor 
nerve,  the  precedent  motion,  characteristic  of  the  muscle  irritated, 
is  produced  in  that  nerve. 

Resistances  vary  as  cross-sections  and  numbers  of  nerves, 
hence,  different  motor  nerves  require  different  quantities  of 
molecular  energy. 

By  all  means,  the  reader  should  avoid  conceiving  of  the 
forces  or  energies,  herein  alluded  to,  as  material  entities.  No 
force  is  a  substance,  but  all  forces  are  conditions  or  states  of 
substances.  When  motions  occur  in  masses  or  molecules, 
there  has  been  a  transferral,  a  propagation,  of  the  motion  from 
one  molecule  to  the  neighboring  molecules.  As  there  is  no 
effect  without  an  antecedent  cause,  the  ultimate  primary  orig- 
ination of  motion  is  the  cause  of  all  activity  in  the  Universe, 
and  all  thoughts,  speech,  or  other  deeds,  are  the  consequences 
of  an  endless  chain  of  previous  activities  in  the  individual  and 
his  ancestors. 

The  potential  energy,  the  possibility  of  moving,  exists  in 
muscles  and  await  the  stimulus  to  evoke  contractions  in  them. 
Nerves  are  potentially  energetic,  and  molecular  movements 
which  afford  stimuli  to  the  muscles,  exist  in  motor  nerves. 
These  become  kinetic,  or  active,  when  stimulated  in  turn  by 
the  neuroglia  movements,  which  originate  through  irritations 
from  other  parts. 

According  to  Gerlach,*  and  as  can  be  seen  by  direct  inspec- 
tion, the  more  the  motor  function  of  a  fibril  becomes  evident, 
the  larger  is  it  relatively  to  associated  evidently  sensory  fibrils 
in  the  same  tracts  or  areas.  Though  many  motor  are  smaller 
than  many  sensory,  and  great  ranges  of  sizes  exist  between 

*  The  Spinal  Cord,  Strieker's  Histology. 
10 


146  CLEVENGEK — Physiology  and  Psychology. 

fibers  of  similar  function,  associated  action,  I  think  I  am  safe 
in  predicting,  will  be  found  to  entail  relatively  larger  fibrillar 
cross-section  upon  motor  function. 

Sensory  fibers  and  cells  are  relatively  smaller  than  motor  fibers 
and  cells  when  associated  physiologically  with  one  another. 

As  before  mentioned,  use  determines  the  size  of  nerve  and 
cell,  hence,  the  large  cells  of  Purkinje,  in  the  cerebellum,  and 
the  great  size  of  those  in  the  auditory  nuclei,  though  related 
to  sensory  function,  must  be  taken  in  connection  with  the  net- 
work of  finest  fibrils  in  the  auditory  nuclei,  which  Meynert 
mentions  as  "of  all  the  masses  of  the  gray  floor  the  most 
closely  interwoven  with  fine  fasciculi." 

Henle  *  mentions  an  average  of  fifteen  mmm.  for  motor  and 
ten  mmm.  for  sensory  diameters,  but  calls  attention  to  the  rel- 
ativity of  these  measurements,  the  larger  fibrils  reducing  to 
smaller  in  their  terminations.  Efference  is  quantitatively 
greater  than  afference,  and,  as  Spencer  notes,  the  centrifugal 
waves  are  the  stronger. 

When  the  requisite  quantity  of  energy  is  produced  in  the 
central  area,  through  afferent  irritation,  the  reflex  motor  act 
follows. 

The  differences  of  stimuli  rates  required  to  contract  red  and 
pale  striated  muscles,  tetanically,  are  ten  in  the  former  to  twenty 
to  thirty  in  the  latter,  per  second,  and  indicate,  probably,  better 
facilities  for  quantitative  conduction  in  the  case  of  red  muscles, 
though  the  rates  of  contraction  of  muscles  being  quicker  in  in- 
sects than  in  frogs,  and  in  heart  muscle  than  in  intestinal  smooth 
muscles,  bear  upon  differences  inherent  in  the  muscles  them- 
selves. Sympathetic  fiber  resistance,  however,  is  relatively 
greater  than  in  other  nerves,  owing  to  the  relatively  smaller- 
sized  fibres  that  system  contains.  The  19^  muscle  beats  of 

*  Handbuch  der  Systematic chen  Anatomic,  Nervenlehre. 


CLEVENGER — Physiology  and  Psychology  147 

Helmholtz  denotes  the  meeting  of  quantity  impulses  needed 
to  convulse  a  muscle. 

Francke  and  Pitres*  deduce  from  their  experiments  that 
motor  excitations  transmitted  through  the  cord  pass  only  10 
metres  per  second.  Helmholz  and  Baxt  say  that  cooling  a 
motor  nerve  caused  the  speed  of  transmission  to  fall  from  33 
to  30  m.,  and  when  heated,  accelerated  it  89.4  m.  According 
to  Foster,  sensory  impulses  vary  from  26  m.  to  44  m.  or  more 
a  second.  He  concludes  that  sensory  impulses  do  not  differ 
in  speed  from  motor,  essentially. 

As  between  sensory  and  motor  speeds,  I  incline  to  think 
that  relativity  here  comes  in  with  resistance  and  energy,  pro- 
portioning the  speed  regardless  of  mere  name  of  the  nerve. 

The  diffusion  caused  by  fright  causing  the  knees  to  knock, 
extreme  weakness,  and  the  fact  that  over-exercise  of  one  set 
of  nerves  occasions  weakening  of  the  general  nervous  system, 
shows  the  dependence  of  the  entire  system  upon  the  relativity 
of  its  motions,  and  that  special  abstraction  of  energy,  either 
in  intensity  or  quantity,  entails  general  abstraction  of  nerve 
force. 

To  account  for  the  great  number  of  nerve  fibrils,  we  must 
restrict  the  wave  lengths  to  sets  of  nerves  especially  adapted 
to  entertain  wave  lengths,  or  consider  that  nerves  differ  in  sus- 
ceptibility to  different  intensities  or  quantities  of  molecular 
motion.  One  wire  suffices  in  telephony  and  telegraphy  to 
pass  countless  millions  of  vibrations  of  different  lengths  and 
amplitudes. 

By  analogy  I  would  prefer  the  view  that  all  nerves  convey 
all  ranges  of  wave  lengths  common  to  any  nerve,  but  the  cross- 
section  determines  the  quantities  of  motion  they  were  capable  of 
conveying. 

*  Gazette  des  Hopitaux,  Dec.,  1877. 


148  CLEVENGER — Physiology  and  Psychology. 

Simple  reflexes  occur  when  the  accumulated  centric  vibra- 
tions are  generated  in  quantity  sufficient  to  saturate  the  motor 
nerve  or  reach  the  point  requisite  to  induce  the  production  of 
the  requisite  quantity. 

Compound  reflexes  are  produced  through  the  quantity  suf- 
ficing to  supply  or  propagate  force  in  another  nerve. 

The  alternate  exertion  of  bilateral  groups  of  muscles  con- 
sists of  the  easier  transfer  of  irritations  from  the  exhausted 
side  to  the  nerve  roots  of  the  rested  side. 

The  walking  of  vertebrates  generally,  and  the  swimming  of 
the  fish  through  alternate  exercise  of  muscles  on  both  sides 
are  instances. 

Compound  reflexes  are  only  coordinated  through  much 
training,  and  involve  not  only  the  building  up  of  the  necessary 
correlating  fibers,  but  the  regulation  of  their  sizes  to  the  de- 
mands made  upon  them. 

In  what  does  inhibition  consist  ?  We  know  that  in  spite  of 
stimulation,  a  muscle  may  resist  action.  A  channel  for  diffusion 
seems  to  be  afforded,  but  two  opposing  currents,  acting  simul- 
taneously, nullify  the  effects  of  both.  When  two  contrary 
impulses  are  generated,  the  resultant  is  zero.  In  a  checked 
impulse  to  go  forwards,  for  example,  the  impulse  necessary  to 
do  so  is  too  feeble,  the  generated  waves  are  not  sufficient,  but 
in  doubt  whether  to  turn  to  the  right  or  left,  both  groups  of 
motions  are  alternately  feebly  excited,  but  strongly  enough  to 
swerve  the  body  in  both  directions,  but  other  channels  are  also 
operated  upon,  diverting  the  currents.  In  complex  phenomena 
such  as  these  we  are  apt  to  lose  sight  of  the  simple  conditions 
upon  which  they  depend.  One  reflex  being  possible,  another 
is  also  possible,  the  correlation  of  these  two  reflexes  succeeds 
by  division  of  currents  between  them,  and  the  possible  number 
of  compound  coordinate  reflexes  which  may  follow  are  incal- 
culable. 


CLEVENGER — Physiology  and  Psychology.  149 

Putting  this  into  nerve-force  terms,  we  have :  general  sensi- 
bility io7  to  io7x  2  sufficing  to  saturate  a  motor  nerve,  the 
cross-section  of  which  admits  of  io7  x  i  j£  as  its  quantity,  the 
simple  reflex  results.  The  remainder  of  the  stimulus  being 
diffused  in  adjacent  gray  substance,  but  if  added  to  by  a  sub- 
sequent reverberation  of  io7  x  2  =  io7  x  2  J^,  then  a  more  dis- 
tant organ  in  addition  may  be  stimulated,  their  synchronous 
action  requiring  the  generation  of  a  higher  molecular  action  or 
the  successive  discharges  from  center  to  both  channels.  These 
motions  are  only  practicable  when  the  nervous  system  has 
undergone  adaptation,  adjustment  to  the  conditions  necessary 
to  provoke  them. 

A  protozoon  which  adapts  itself  to  a  change  in  environment 
can  only  do  so  through  environment  reacting  upon  its  molec- 
ular structure  and  making  such  rearrangement  of  its  sarcodal 
elements  as  will  render  further  life  possible  to  it,  just  as  con- 
tinued abrasion  and  impacts  on  palms  of  hands  and  soles  of 
feet  harden  the  dermis  mechanically,  so  that  inconvenience 
from  labor  or  much  walking  is  not  experienced  as  formerly,  so 
in  nerve  and  muscle  tissue  the  physical  basis  of  "becoming 
accustomed"  to  anything  is  in  a  mechanical  or  molecular  re- 
arrangement of  one  or  both  of  these  organs.  Certainly  the 
ability  to  lift  heavy  and  heavier  loads  is  accompanied  by  and 
dependent  upon  the  growth  of  muscles  and,  inferentially, 
nerves. 

Reflexes  consist  of  stimuli  evoking  waves  in  such  speeds, 
lengths,  and  quantities  as  comport  best  with  molecular  motor 
movements  sufficient  to  excite  muscles.  The  cord  reacts  best 
between  nerve  elements  of  the  same  level.  For  reflexes  of 
different  levels  the  stimulus  must  be  increased  or  be  produced 
by  summation  of  other  molecular  movements  to  the  intensity 
and  quantity  that  will  do  the  work.  When  things  are  done  in- 


150  CLEVENGER — Physiology  and  Psychology. 

stinctively,  it  is  by  virtue  of  the  readjustment  which  makes 
the  reflex  easy.  Habit,  instinct,  adapt  means  to  ends  so  effect- 
ually in  proportioning  widths  of  axis  cylinders  to  lengths,  and 
the  whole  resistance  is  lowered  to  the  point  which  makes  re- 
action to  constantly  recurring  certain  stimuli  so  exact  and 
inevitable  as  to  make  deviation  from  acquired  facility  of  mus- 
cular motion  extremely  difficult,  compelling  the  painter  to  use 
his  left  hand  occasionally,  to  overcome  the  precision  of  touch 
which  constitutes  his  "style." 


CLEVENGER — Physiology  and  Psychology,  1 5  i 


CHAPTER  VII. 

PHYSICS  OF  THE  SYMPATHETIC  NERVOUS  SYSTEM. 

With  regard  to  "  trophic  nerves,"  the  general  belief  is  gain- 
ing ground  that  none  such  exist,  but  that  nutritive  changes 
which  follow  nervous  lesions  are  referable  to  vascular  disturb- 
ances. This  is  so  satisfactory  that  it  at  once  transfers  the  mys- 
terious and  inscrutable  to  simple  and  knowable  processes. 
Trophic  influences  are  placed  within  vaso-motor  precincts. 

Lawaschew,*  of  St.  Petersburg,  under  Professor  Botkin, 
elaborates  the  subject,  and  holds  that  dilatation  of  vessels  con- 
sequent on  nerve  lesions  are  often  precursors  of  "  trophic 
changes  "  in  the  tissues  and  due  to  "  irritation  of  the  vaso- 
dilator nerves,"  and  not  to  paralysis  of  the  vaso-motors. 

The  foremost  vaso-motor  stimulant  is  temperature  differ- 
ence, but  other  modes  of  molecular  motion  influence  that  sys- 
tem either  directly  or  indirectly. 

The  vascular  function  is  a  highly  nutritive  one,  and  where 
first  one  part  of  the  body  and  then  another  demanded  blood 
supply  in  excess  of  other  parts,  just  such  slow  rhythmic  pul- 
satile motions  as  are  observed  in  the  vascular  system  would 
follow  engorgement  and  dilatation  of  one  part  would  passively 
effect  distention  of  distant  parts  subjected  to  regurgitant  pres- 
sure, a  to-and-fro  irritation  of  the  arterial  circular  muscles 
would  arrange  commissural  tracts  facilitating  transfer  of  equili- 
bration and  maintenance  of  tonus.  Dilatation  of  one  part 
stimulating  molecular  diffusion  from  other  parts  to  act  as  con- 
strictors, the  calibers  of  the  vessels  are  kept  within  limits. 

*  Centraiblatt  fur  d.  Med.  Wis.,  1883,  p.  193. 


152  CLEVENGER — Physiology  and  Psychology. 

An  equilibrating  electrical  pumping  apparatus  could  be  con- 
structed upon  this  principle.  Around  a  flexible  tube  pass  seg- 
ments of  electro-magnetic  clamps,'  so  arranged  that  when  one 
set  of  clamps  are  pressed  apart  by  over  distention  of  a  part  of 
the  tube,  it  "  short  circuits  "  the  current  passing  over  a  wire 
which  extends  the  length  of  the  tube,  and  causes  the  dis- 
tributed current  to  act  energetically  in  the  part  needing  con- 
striction, entailing  an  expenditure  of  force  which  drops  the 
general  normal  several  galvanometric  degrees. 

Distention  acts  as  a  generator  of  force  (the  increased  heat  and 
other  molecular  interchange  is  evident  in  distended  parts);  this 
suffices  to  raise  the  nerve  vibrations  in  that  part,  and  with  in- 
creased blood  consumption  the  facilities  for  both  muscle  and 
nerve  motion  are  locally  increased,  but  the  diffused  motions 
pass  to  the  general  sympathetic  system  which,  having  its  plane 
of  action  and  exerting  its  usual  tonicity  force  elsewhere,  dis- 
tributes the  pressure.  It  is  evident  that  this  can  be  effected  but 
slowly,  the  mechanism  for  quick  equilibration  between  all  parts 
not  existing,  but  as  Carpenter  *  says  :  "  When  once  a  mode  of 
nutrition  has  been  fully  established  it  tends  to  perpetuate  it- 
self," and,  he  might  have  added,  differentiate  and  develop. 
Between  points  remote  or  contiguous  wherein  fluctuations  are 
extreme,  there  would  arise  better  facilities  for  equalization 
through  simple  development  by  extra  use  of  the  fundamental 
system. 

Antipodal  head  and  abdomen,  with  their  complementary 
alternate  excess  and  diminution  of  blood,  have  built  up  the 
splanchnic  and  cervical  with  the  spinal  sympathetic  commis- 
sures. With  dilatation  of  one  pole  a  channel  affording  least 
resistant  passage  for  a  constricting  influence  would  be  a  desid- 
eratum, and  forces  acting  on  that  line  would  build  it  up. 

*  Human  Physiology,  p.  556. 


CLEVENGER — Physiology  and  Psychology.  153 

Granting  the  constrictor  abilities  of  the  splanchnic  and  cervi- 
cal, how  shall  we  account  for  the  dilatation  through  stimulation 
of  nervi  erigentes,  chorda  tympani,  and  muscular  nerves  ? 

Dilatation  is  a  nutrient  reflex.  Upon  muscular  excitation 
there  is  a  reparative  demand.  If  a  muscle  be  stimulated  to 
contraction,  it  would  seem  proper  that  means  of  repairing  the 
waste  involved  in  the  contraction  should  be  provided.  The 
osmotic  power  of  the  vessels  is  drawn  upon  with  muscular 
action,  occasioning  a  secondarily  induced  rush  of  blood  to  the 
part  being  nourished.  This  being  the  established  action  of  the 
entire  nerve  distribution  in  the  parts  under  consideration,  that 
mode  of  action  would  adjust  both  cerebro-spinal  and  vaso- 
motor  systems  to  its  repetitions,  and  it  must  be  borne  in  mind 
thatvaso-dilator  fibers  run  chiefly  in  the  cerebro-spinal,  vaso  con- 
constrictor  in  the  sympathetic  nerves,  but  even  admitting  the 
dictum  of  Dastre  and  Morat.*  that  vaso-dilator  fibers  exist  in 
the  vago-sympathetic  trunk,  concomitant  phenomena,  such  as 
dilatation  following  exercise  of  a  part,  could  develop  the  molec- 
ular susceptibilities  of  a  nerve  constantly  associated  with  defi- 
nite workings  of  other  nerves  as  to  render  the  dilatation  constant, 
whether  the  motor  or  the  sympathetic  branch  were  irritated. 

Associated  serviceable  habit  developes  the  most  extraordinary 
capabilities  throughout  organic  life,  especially  evident  in  the 
emotions,  as  Darwin  has  shown  so  well. 

Bernstein  f  concludes  that  "  carbonic  acid  dyspnoea "  is 
chiefly  expiratory  in  character ;  the  dyspnoea  caused  by  want 
of  oxygen  is  chiefly  inspiratory.  These  relative  influences  upon 
the  respiratory  center  of  excess  of  CO2  and  want  of  oxygen  in 
the  blood  can  only  be  demonstrated  by  cutting  off  the  vagus 
control.  . 

*  Arch.  H.  Physiol.  Norm,  et  Path.,  1882,  I,  2,  and  3  ;  and  Centralblatt  f.  d. 
Med.  Wis.,  1882,  p.  731, 

f  Du  Bois- Raymond's  Archiv.,  1882,  p.  313. 


154  CLEVENGER — Physiology  and  Psychology. 

Blood  condition  in  a  center  can  become  associated  with  dis- 
tant movements,  calculated  to  alter  the  nutrition  of  the  irritated 
point  for  the  better,  and  whether  through  paralysis  of  a  strand 
or  through  stimulation,  the  adjustment  of  the  nerve  to  its  func- 
tion may  result  in  diametrically  opposite  modes  of  working. 
The  apparently  erratic  conversion  of  constrictors  into  dilators 
and  vice  versa  are  best  accounted  for  by  Lepine's*  experiments 
on  the  frog's  sciatic,  the  conclusion  from  which  is  that  the  same 
fiber  may  act  as  dilator  or  constrictor,  according  to  the  condition 
of  the  peripheral  mechanism.  Foster  f  suggests  that  the  paths 
along  which  the  impulses  of  afferent  or  central  origin  issue  as 
efferent  impulses  are  determined  in  part  by  the  condition  of  the 
cord  and  character  of  the  afferent  impulses,  or  of  the  central 
disturbance. 

The  vaso-motor  phenomena  attending  every  reflex,  whether 
cerebro-spinal  or  sympathetic,  are  of  more  importance  than 
could  be  judged  from  their  little  consideration  by  writers.  The 
assumption  of  a  vaso-motor  accompaniment  to  every  act  of 
the  nervous  system  involves  an  explanation  of  much  hitherto 
considered  inexplicable.  No  blood,  no  action ;  plus  blood, 
plus  action.  Every  vital  act  incurs  expenditure,  sensation  as 
well  as  motion.  The  irritation  of  every  cell  causes  waste,  and 
necessitates  repair.  If  the  reparative  (vaso-motor)  power  be 
annulled,  the  function  ceases  with  death  of  the  part.  Regen- 
eration of  nerve  areas  must  be  regarded  as  identical  with  that 
of  any  other  tissue.  The  brain  is  nourished  precisely  as  are 
other  organs,  reflexly  through  irritation  at  the  point  needing 
restoration.  Molecular  change,  depletion,  expenditure  is  the 
irritant.  The  amoeba  moves  more  rapidly  when  hungry  than 
after  being  fed.  The  vaso-motor  is  the  reparative  system,  and 

*  Comp.  Rend.  Soc.  Biol.,  March  4th,  1876. 
f  Physiology,  p.  284. 


CLEVENGER — Physiology  and  Psychology.  1 5  5 

its  reflexes  must  be  considered  with  reference  to  that  function, 
regardless  of  but  little  else.  Such  visceral  parts  as  use  blood 
most  rapidly  are  in  the  greatest  condition  of  vaso-motor  irri- 
tation. Habit  fixes  the  quantity  of  blood  and  regulates  its 
afflux.  The  vaso-motor  connections  with  the  cerebro-spinal 
system  have  the  same  significance  as  their  connection  with 
other  organs.  Splenetic,  gastric,  uterine,  hepatic,  etc.,  irrita- 
tion, through  want  of  blood,  starts  the  reflux,  and  no  matter 
whether  sensory  or  motor  nerve  needs  restoration,  the  irrita- 
tion of  either  will  start  vaso-motor  action  as  readily  as  to  ab- 
dominal viscera. 

The  connection  of  sympathetic  fibers  with  both  sensory  and 
motor  cerebro-spinal  nerves  has  no  other  value  than  that  the 
vaso-motor  system  recks  of  molecular  motion  without  dis- 
crimination as  to  whether  those  motions  produce  sensations  or 
muscular  actions.  If  a  sensation  pass  over  a  spinal  nerve,  mole- 
cular motions  are  set  up  in  that  nerve  and  stimulate  vaso-motor 
action  ;  if  a  motor  nerve  be  engaged,  both  nerve  and  muscle 
thereby  excite  vaso-motor  afflux  of  blood  to  them.  But  due 
regard  must  be  paid  to  the  blood  conveyance  in  the  entire 
animal,  for  a  disturbance  at  a  distance  may  render  stimulation 
of  other  parts  inoperative.  Hence,  the  variable  nature  of  sym- 
pathetic workings  may  be  represented  by  the  active  points 
ABCDE,  having  a  tonus  of  10  along  their  vaso-motor  filaments. 
A,  being  stimulated  to  contractile  effect  20,  BCDE  vessels  at 
first  are  dilated  by  blood  pressure,  but  by  diffusion  the  general 
tonus  is  distributed  as  12  to  all  points.  Let  E  demand  repair 
through  exhaustion,  lowering  the  tonus  of  E  to  zero,  then  the 
remaining  tonus  of  all  falls  to  9.6.  Now  let  C  and  E  require 
blood  before  the  vessels  at  E  have  been  restored  to  their  usual 
calibre,  ABD  will  be  in  tone,  C  dilated,  and  E  extremely  di- 
lated. It  is  plain  that  a  strand  ordinarily  acting  as  a  constrictor 


156  CLEVENGER — Physiology  and  Psychology. 

at  A,  could  not  thus  act  at  this  stage,  but  would  appear  to  act 
as  a  dilator,  through  its.  stimulation  having  aided  in  raising  the 
tone  of  C  and  E,  the  general  distribution  causing  the  tone  at 
A  to  fall. 

The  vascular  tonus  being  normal,  generally,  in  the  "  indiffer- 
ent regions,"  there  will  follow  dilatation  if  other  vascular  regions 
are  dilated,  through  the  diffusion  acting  first  to  re-establish 
tonus,  the  dilatation  being  compensatory  in  the  region  apparently 
stimulated. 

Vaso-constriction  is  the  usual  effect  of  vaso-motor  irritation. 
Vaso-dilatation  may  become  the  normal  effect  pf  stimulation  of 
a  vaso-motor  nerve,  by  associated  influence  of  cerebro-spinal 
nerves,  or  by  diffusion  of  vaso-constriction  to  adjacent  vascular 
regions  with  minus  tonus,  such  minus  tonus  may  be  the  effect 
of  the  same  stimulation  which  produces  the  apparent  dilatation, 
through  action  stimulated  in  those  adjacent  parts  (  muscular, 
usually  ),  or  the  minus  tonus  may  be  caused  by  synchronously 
operative  distant  causes.  Habit,  adaptation,  or  readjustment  will 
thus  implant  dilating  instead  of  constricting  function  upon  cer- 
tain vaso-motor  regions.  In  the  simplest  possible  language, 
if  other  accessible  parts  need  constriction  or  restoration  of  tonus 
most,  diffusion  in  lines  of  least  resistance  will  occur,  and  the 
apparent  dilatation  of  the  near  point  is  the  afflux  of  equilibra- 
tion. A  part  having  this  mode  of  action  established  would 
develop  facilities  for  diffusion  of  stimulation  to  the  other  parts 
and,  by  relativity  of  forces,  the  near  part  would  be  paralyzed, 
and  dilatation  become  extreme  in  that  part  on  stimulation. 


CLEVENGER — Physiology  and  Psy etiology. 


CHAPTER    VIII. 

PHYSICS  OF  THE  NERVE  CELLS. 

Thus  far  I  have  purposely  avoided  any  mention  of  nerve 
cells  or  ganglia  participating  in  nervous  or  mental  workings. 
When  I  affirm  that  there  are  many  and  good  reasons  for  re- 
garding the  main  function  of  the  nerve-cell  to  be  histogenesis, 
and  that  all  the  workings  of  nerves  proper,  and  the  sensitive 
basis  substance,  such  as  the  neuroglia  of  the  spinal  cord  and 
brain  cortex,  are  best,  or  equally  as  well,  studied  without  refer- 
ence to  the  nerve  cells,  I  state  that  which  needs  defence ;  but 
the  acceptance  or  rejection  of  the  histogenetic  function  view 
and  the   refusal   to  concur  in  or  adherence  to  the  olden  view 
of  the  nerve  cell  being   an  energy-producing  body,  does  not 
affect,  in  the  least,  the  value  of  the  deductions  or  inferences  up 
to  this  point,  nor   those  to  follow.      There  is  no  dependence 
of  tlie  inferences  mentioned  upon  the  correctness  or  incorrectness 
of  my  theory  that  the  nerve  cell  is  a  cell,  correctly  so  named,  with 
highly  reproductive  powers,  and  very  small  and  few  other  powers. 
In  saying  that  this  assertion  needs  defence,  it  must  be  re- 
membered that  the  olden  theory  of  force-production  function 
on  the  part  of  the  nerve-cell  needs  equal  defence,  and  is  an  as- 
sumption of  the  broadest  kind,  to  sustain  which  the  most  triv- 
ial reasons  have  been  offered  in  the  face  of  much  evidence  to 
sustain  a  contrary  view. 

March  n,  1881,  I  advanced  my  histogenetic  nerve-cell  the- 
ory in  a  paper  read  before  the  Illinois  State  Microscopical  So- 
ciety,* and  made  it  the  subject  of  my  American  Neurological 

*  An  abstract  of  which,  full  of  typographical  errors,  appears  in  the  Chicago 
Medical  Review,  March  2Oth,  1881. 


158  CLEVENGER — Physiology  and  Psychology. 

Association  thesis  at  its  June,  1881,  meeting.  The  grounds 
for  my  conclusions  are  as  follows : 

The  nerve-fiber  and  not  the  nerve-cell  is  the  first  to  arise  in 
forms  above  the  protozoa,  as  in  Kleinenberg's  Hydra,  Pseu- 
donematon,  and  other  low  worms.  In  noto-chordal  animals 
such  as  the  amphioxus  an  elaborate  system  of  nerves  exists 
without  a  nerve-cell  being  present. 

Free  nuclei  and  neuroglia  abound,  such  as  Schmidt*  and 
othersf  observed  in  the  human  embryonal  nervous  system, 
where  nerve-fibrillae  cluster  about  nuclei,  the  fibrillae  arranging 
themselves  in  rows  and  fasciculi.  "The  pia  mater  extends 
from  the  brain  and  spinal  marrow  over  the  peripheral  nerves 
in  the  form  of  a  single  sheath.  The  whole  nerve  consists 
therefore,  like  the  nerve  of  an  insect,  only  of  a  bundle  of  gran- 
ular fibrillae,  which,  in  pursuing  a  wave-like  course,  are  placed 
parallel  to  each  other,  and  surrounded  by  their  sheath  and 
neurilemma"  (Schmidt,  op.  cit.)  He  also  mentions  "mother- 
cells  "  packed  with  larger  and  smaller  nuclei.  Multiplication 
of  nuclei  by  endogenous  modes  ceases  at  one  stage  and  gem- 
mation begins. 

The  nerve-cell  is  born  of  the  original  protoplasmic  cell,  and 
is  highly  productive  of  granules,  which  form  axis-cylinder  pro- 
cesses. 

Deitl  J  agrees  with  Mayer  in  assigning  axis  cylinder  rein- 
forcing properties  to  nerve-cells,  and  both  consider  the  sympa- 
thetic nerve-cell  as  a  reserve  material  for  the  reproduction  of 
the  nerve-fibers  that  have  become  unsuitable  for  the  transmis- 
sion of  nervous  influence.  "  For  this  development  the  nerve- 
cells  utilize  the  elements  of  the  blood,  notably  the  red  glob- 
ules. We  find  in  the  sympathetic  in  the  vicinity  of  blood- 
vessels special  elements  formed  of  a  fundamental  substance 
and  numerous  nuclei,  analogous  as  regards  form  and  micro- 
chemical  reactions  to  the  blood  globules.  The  fundamental  sub- 

*  The  Development  of  the  Tissues  of  the  Human  Embryo,  Journal  of  Nervous 
and  Mental  Disease,  July,  1877. 

f  Histology  of  New-Born  Cortex.     Brain,  July,  1883,  p.  287. 
J  Sitzungb.  der  K.  Akad.  der  Wissensch.,  1874. 


CLEVENGER — PJiysiology  and  Psychology.  159 

stance,  closing  gradually  around  these  nuclei,  form  masses  of 
protoplasm  which  slowly  take  on  the  appearance  of  nerve- 
cells.  These,  apolar  at  first,  later  present  a  prolongation  which, 
uniting  itself  with  one  or  another  cell,  forms  a  nerve-fiber." 
Mayer's  researches  on  the  sympathetic,  and  Deitl's  upon  other 
ganglia,  make  the  application  general.  Kolliker,  Beale,  and 
Henle  hold  the  division  of  nerve-cells  into  others.  Thus  not 
only  is  the  reproductive  faculty  highly  exalted  in  the  direction 
of  axis-cylinder  formations,  but  also  for  cells  of  its  own  kind. 
It  is  a  simple  biological  principle,  that  development  of  a  faculty 
in  one  direction  involves  suppression  without  necessary  ex- 
tinction of  other  attributes.  It  is  inconceivable  that  the  nerve- 
cell  should  possess  two  highly  differentiated  peculiarities. 
Hence  its  energy  origination  must  be  in  abeyance. 

Fibers  may  be  and  are  produced  primitively  independently 
of  nerve-cells. 

The  brain  and  spinal  cord  of  the  embryo  is  one  large  nerve- 
cell. 

The  nerve-cell  is  not  necessary  to  nerve  action,  for  in 
the  lowest  vertebrate  there  is  an  utter  absence  of  such  cells, 
the  fibers  alone  affording  passage  for  this  form  of  molecular 
motion. 

Dr.  Roler,  of  Chicago,  obstetrician,  told  me  five  years  ago 
of  a  case  in  his  experience  of  an  anencephalous  child,  whose 
vigorous  kicks  in  the  course  of  delivery  led  the  doctor  to 
diagnose  anencephalism  before  birth,  as  he  had  just  read  in  the 
American  Journal  of  Obstetrics  of  a  similar  case  of  explosive 
reflex  irritability  in  the  delivery  of  a  similar  monster.  Now,  if 
this  is  a  common  anencephalic  accompaniment  on  the  basis  of 
nerve-cell  genesis  of  force,  how  can  this  be  accounted  for  when 
the  millions  of  cerebral  nerve-cells  are  absent? 

The  neuroglia  sizes  decreasing  in  the  cortex  in  proportion 
to  their  development  of  fibrillae  (Stilling  and  Meynert  regard 
the  neuroglia  as  essentially  a  felt-like  substance  composed  of 
the  most  indirect  and  finest  nerve  processes),  show  that  sensa- 
tion and  molecular  energy,  of  which  the  former  is  one  expression 
of  the  latter,  reside  in  the  neuroglia,  and  that  fibrillar  develop- 


160  CLEVENGER — Physiology  and  Psychology. 

ment  is  the  great  desideratum  in  increasing  facilities  for  mole- 
cular interchange  of  a  nervous  nature.  Every  cell  in  the 
body,  every  nerve-fiber  is  capable  of  molecular  motion,  and 
though  the  nerve-cell  is,  as  Spitzka  *  says,  "  the  ultimate 
functional  center  of  the  nervous  system  in  man  and  other 
higher  animals,"  the  parallel  fact,  which  he  also  cites,  that  in- 
creasing intelligence  and  coordinations  go  hand  in  hand  with 
increase  of  commissural  nerve-fiber  establishment,  show  that 
the  increase  in  fibrillar  connections  requires  the  increase  in  his- 
togenetic  arrangements,  such  as  we  find  eminently  provided  for 
by  nerve-cell  increase. 

I  regard  the  olden  assumption  of  autocracy  for  nerve-cells 
as  the  last  foothold  of  that  superstition  which  pictured  flesh- 
less  bones  stalking  abroad  at  midnight.  The  sizes  of  these 
cells  would  be  in  proportion  to  the  stimulation  they  sustained 
toward  granule  parturition,  and  the  immense  number  of  fine 
fibrillae  near  the  internal  auditory  nucleus  is  a  case  in  point. 
Cells  such  as  the  auditory,  and  the  giant  pyramidal  of  Betz_ 
are  certainly  under  constant  strain.  When  any  mechanical, 
chemical,  or  electrical  irritation  suffices  to  stimulate  nerves, 
the  creation  of  a  special  stimulating  apparatus  other  than  such 
as  exist  in  amphioxus,  dipnoi,  etc.,  would  be  unnecessary, 
Goltz  tacitly  admits  the  direct  stimulation  of  the  nerve-fibers 
without  cell  intermediation,  in  criticising  Ferrier's  experiments. 

The  associated  atrophy  of  nerve-cells  and  fibers,  such  as 
Davidaf  found  in  perobrachia  (arrested  development  of  the 
forearm)  and  pathologists  frequently  find  in  tract  degeneration, 
bear  in  the  direction  of  the  failure  of  cell  stimulation  through 
nerve  destruction,  for  an  organ  ceasing  to  act  through  want  of 
stimulation  will  atrophy,  but  an  organ  which  stimulates  need 
not  die  because  that  which  it  stimulates  has  perished.  The 
nerve  being  the  stimulator  and  the  cell  the  stimulated  body, 
nerve-cells  may  atrophy  without  entailing  destruction  of  nerve- 
fibers,  except  where  the  so-called  trophic  relationship  exists, 

*  Architecture  and  Mechanism  of  the  Brain. 
fVirchow's  Archiv,  April,  1882. 


CLEVENGER — Physiology  and  Psychology.  161 

which  seems  to  indicate  the  dependence  of  the  nerve  upon  the 
cell  for  its  elements ;  otherwise  Wallerian  degeneration  of 
nerves  would  be  centripetal  instead  of  centrifugal.  The  nerve 
destruction  in  this  case  does  not  cause  cell  destruction,  but  if 
the  stimulating  area  in  which  that  cell  reposed  were  function- 
less,  the  cell  would  die,  but  not  the  centripetal  nerves. 

The  diversified  shapes  of  nerve-cells  seem  to  bear  relation 
to  the  composition  of  forces  rather  than  diversity  of  function. 
The  lines  in  which  impinging  energies  act  determine  shapes  of 
other  tissues,  and  speculations  in  this  direction  applied  to 
nerve-cells  would  be  fruitful.  The  fusiform  bipolar  cell  could 
result  from  forces  traversing  it ;  the  globular  unipolar,  from 
forces  terminating  in  it;  the  multipolar,  from  varying  quanti- 
ties of  energy  acting  in  several  directions ;  the  pyramidal,  from 
having  its  point  of  greatest  tension  at  the  base,  with  least  re- 
sistance at  the  large  tapering  process.  Always  remembering 
that  these  cell  activities  appear  to  be  mainly  histogenetic,  and 
the  stimulation  it  receives  serves  to  elongate  the  process  and 
promote  the  more  rapid  formation  of  nerve-granules  and  fibrils, 
but  there  is  nothing  to  prevent  the  cell-contents  from  acting  pre- 
cisely as  do  other  fibrilla  in  the  conduction  of  motion.  The  gan- 
glionic  bodies  Ranvier,  Max  Shultze,  Schmidt,*  Deiters,  and 
others  have  shown  contain  multitudes  of  fibrillae  and  granules 
of  minute  sizes. 

All  investigation  goes  to  show  the  precedence  of  the  nerve 
granules  which  are  formed  into  rows  and  fasciculi,  and  that 
nerve  action  precedes  the  appearance  of  the  nerve-cell.  The  lat- 
ter is  formed  at  a  stage  when  greater  multiplication  of  granules 
and  fibrillse  proceed,  and  the  cell  is  formed  from  these  pre-ex- 
isting elements,  in  my  opinion,  for  the  purpose  of  hastening 
the  granular  and  fibrillar  creation. 

*  Schmidt's  researches  and  engravings  in  the  Journal  of  Nervous  and   Men- 
tal Disease,  Jan.,  1879,  are  excellent. 
11 


1 62  CLEVENGER — Physiology  and  Psychology. 


CHAPTER  IX. 

PHYSICS  AND  CHEMISTRY  OF  THE  NERVOUS  SYSTEM. 

However  the  Liebig,  Meyer,  Voit,  Traube,  Matteucci,  Heid- 
enhain,  Hermann  controversy  may  be  reconciled,  an  extension 
of  the  hypothesis  of  the  latter  to  the  protagon  activities  of  the 
brain  affords  satisfactory  analogies.  The  phosphorized  nitro- 
genous cerebral  substance  exhales  the  same  gas,  CO2,  into  the 
blood,  and  uses  up  oxygen  as  does  muscle.  Cholesterin  bears 
some  such  relationship  to  the  nerves,  urea  and  other  such 
crystals  do  to  the  muscles,  and  in  the  elimination  of  cholesterin 
the  liver  is  associated  with  the  nervous  system  as  the  kidneys 
in  the  elimination  of  urea  and  its  congeners  are  with  the  mus- 
cles. The  distinction  between  cholesterin  and  the  urea  group 
seems  to  be  the  absence  of  nitrogen  from  the  former  and  its 
presence  in  the  latter.  The  distinction  between  protagon  and 
inosine  is  the  presence  of  phosphorus  in  the  former.  The 
oxidation  of  the  phosphorus  and  its  union  with  the  cyanitics, 
with  liberation  of  cholesterin  and  CO2,  with  accompanying 
propulsion  of  exploded  particles  apart,  the  seggregative  nerve 
property,  have  complementary  characteristics  in  the  muscular 
ammonium  cyanogen  change  to  urea  and  concomitant  conver- 
sions producing  contractions  by  aggregation  of  molecules. 
Such  increases  and-  decreases  of  bulk  and  specific  gravities  in 
the  union  of  chemical  solutions  are  familiar  to  tyros  in  chem- 
istry. 

Phosphorus  has  a  great  affinity  for  oxygen,  and  cyanogen 
enters  into  combination  with  the  non-metallic  elements,  as 


CLEVENGER — Physiology  and  Psychology.  163 

though  it  were  itself  an  element  Chlorides,  bromides,  and 
iodides  of  cyanogen  are  easily  formed,  facts  which  have  both 
physiological  and  therapeutical  bearings. 

Kopp  *  says  phosphorus  expands  3.43  per  cent,  at  the  mo- 
ment of  fusion  at  44°  C,  but  contracts  like  wax  and  sulphur 
on  cooling.  Phosphorus  assumes  several  different  forms  under 
the  influence  of  causes  apparently  trifling.  Thus,  while  in 
muscles  there  is  combustion  and  shrinkage,  in  nerves  there  is 
combustion  and  explosive  repulsion. 

The  increased  cerebral  blood-supply  during  thought  and  the 
intoxication  produced  by  oxygen  are  evidences  of  the  rapidity 
of  protagan  interchanges. 

The  evolution  of  heat  being  definite  in  oxygenation,  the  more 
rapid  molecular  interchange  in  higher  animals  is  accompanied 
with  higher  heat-rate.  Electricity  is  definitely  produced  also, 
as  shown  by  Hermann  in  his  inogene  studies,  and  where  this 
had  served  a  useful  purpose  in  perpetuating  the  life  of  an 
animal  with  a  morbid  condition  of  muscular  excitability, 
it  is  likely  enough  that  natural  selection  would  seize  upon  it. 
The  heat  given  out  during  the  combustion  of  a  compound 
body  is  less  than  that  emitted  by  the  combustion  separately  of 
a  quantity  of  each  of  its  constituents  equal  in  amount  to  that 
present  in  the  compound  burnt.f  The  amount  of  heat  disen- 
gaged by  H,  CO2,  CHN,  Fe,  Sn,  SnO,  and  P  with  equal  weights 
of  oxygen  is  nearly  the  same,  except  that  in  phosphorus  it  is 
the  greatest. 

The  heat-rate  of  an  animal  is  at  first  only  an  epiphenome- 
non,  but,  like  everything  else  which  occurs,  must  be  reckoned 
as  in  its  environment,  initially  a  product  of  life,  it  must  be 
allowed  for  when  it  increases  the  molecular  speeds  by  reacting 

*Liebig's  Anal.,  xciii.,  129. 

f  Miller's  Chemistry,  vol.  i.  p.  401. 


164  CLEVENGER — Physiology  and  Psychology. 

upon  the  basis  substances.  The  heat  evolved  by  the  animal 
adjusts  the  molecular  rates,  and  becomes  a  part  of  the  life- 
phenomena,  alterations  of  which  entail  changes  proportionally 
more  or  less  formidable.  Similarly  adaptation  or  readjustment 
suggests  that,  in  muscular  susceptibilities,  various  stimuli  being 
adopted  as  a  normal,  it  is  conceivable  that  muscles,  as  well  as 
nerves,  must  be  considered  as  educable  or  adjustable,  and  be- 
come non-responsive  to  stimuli  often  repeated  through  molecu- 
lar rearrangements.  Muscles  hence  must  vary  between  themselves 
as  to  their  selective  response  to  stimuli,  and  thus  much  of  the 
burden  of  compound  reflexes  may  be  greatly  lifted  from  the 
nervous  system. 

The  protozoon  exists  in  an  environment  of  nitrogen  and 
oxygen,  the  former  inert  and  the  latter  a  food  in  its  affinities 
for  protoplasmic  derivatives.  The  combined  H2O  have  a  main 
significance  as  a  vehicle  for  molecular  interchange,  facilitating 
the  necessary  atomic  and  molecular  translocations.  Nitrogen 
has  a  persistent  tendency  towards  its  free  inert  state,  and  this 
very  disposition  confers  upon  it  great  physiological  import- 
ance. On  the  other  hand,  oxygen  has  a  great  antipathy  to  un- 
combined  existence.  These  two  mechanically  mixed  ingredi- 
ents of  the  air  play  in  biological  phenomena  complementary 
parts. 

Phosphorus  in  its  assimilable  form  of  the  tricalcic  diphos- 
phate  conveys  its  bone-producing  properties  in  connection  with 
the  attributes  of  gelatin  for  its  solution.  The  sudden  appear- 
ance of  large-boned  vertebrates  in  a  phosphorite  epoch  was 
noted  by  Prof.  E.  D.  Cope,*  and  Filhol  f  subsequently  re- 
marked the  same  thing.  The  profound  modifications  which 
the  paleontologists  convince  us  animal  life  underwent  through 

*Hayden's  Reports. 

|  Phosphorites  of  Quercy,  1878. 


CLEVENGER — Physiology  and  Psychology.  165 

accidental  advantageous  surroundings  undoubtedly  include  the 
presence  of  assimilable  phosphorus  in  plants,  and  accompanying 
physiological  possibilities  for  its  assimilation.  The  differences 
in  the  excreta  of  the  vertebrate  division  show  that  materials 
made  vital  to  a  higher  life  through  systemic  absorption  and 
utilization  are  inert  excrementitious  matter  in  the  lower  ani- 
mals. The  acidity  of  muscle  and  nerve  substance  in  connec- 
tion with  blood  alkalinity,  render  possible  the  conveyance  of 
alkaloids,  and  make  it  likely  that  soluble  alkaloidal  hydro- 
carbons of  the  neurotic  group,  assimilable  by  the  organism, 
have  sufficiently  close  molecular  resemblances  to  the  acid  pro- 
tagdn  as  to  account  for  their  mutual  affinities  and  bio- 
chemistry. 

The  differences  in  the  physical  attributes  of  the  great  neu- 
rotics are  not  apparent  in  their  respective  proportions  of  car- 
bon, hydrogen,  nitrogen,  and  oxygen.  There  are  some  marked 
relationships  between  quantivalence,  atomic  weights,  numbers 
of  molecules,  and  physical  properties  of  compounds,  as  well 
as  in  elements ;  but,  aside  from  such  examples  as  Kopp's  law 
of  boiling  points  of  ethers,  the  temperature  increasing  with  the 
numbers  of  CH2  atoms ;  in  general,  the  chemical  formulae  of 
substances  afford  no  clues  to  their  modus  operandi  with  respect 
to  heat,  light,  electricity,  etc.,  and  comparatively  little  has  been 
done  to  tabulate  from  direct  experiments  such  peculiarities. 
The  rationale  of  the  neurotics  and  medicines  generally  is  a 
a  tempting  field  for  speculation.  The  bitterness  of  most  tonics, 
the  fact  that  tannic  acid  kills  paramecia,  the  alkalinity  of  am- 
monia in  connection  with  the  acidity  of  nerves  and  muscles, 
the  poisonous  properties  of  phosphorus  being  increased  by 
fatty  matters,  the  nutritive  interferences  m  toxaemia,  etc.,  with 
such  investigations  as  Spitzka*  on  strychnia  would  afford  the 

*  The  Anatomical  and  Physiological  Effects  of  Strychnia  on  the  Brain,  Spinal 
Cord,  and  Nerves,  Journal  of  Nervous  and  Mental  Disease,  April,  1879. 


1 66  CLEVENGER — Physiology  and  Psychology. 

chemist  most  satisfactory  considerations.  The  carbonization 
of  the  blood  in  hydrocyanic  acid  poisoning  refers  to  a  central 
toxic  action.  Hensinger,  quoted  by  Darwin,*  notes  that  white 
sheep  and  pigs  are  differently  affected  by  vegetable  poisons 
from  colored  individuals.  Such  differences  may  be  due  to  the 
presence  or  absence  of  pigment  compounds  which  have  affin- 
ities for  or  resist  the  influence  of  certain  poisons.  In  the  con- 
stitution of  protoplasm,  as  well  as  that  of  any  organic  or  inor- 
ganic compound  whatever,  there  is  an  ever-present  necessity 
for  the  absence  of  certain  molecular  groupings  which  would 
destroy  the  combinations  under  consideration  or  cause  them 
to  act  erratically.  The  cell  environment  is  reached  by  adapt- 
ability, and  in  the  differentiation  of  cells  it  is  easily  seen  that 
what  would  be  nutrient  to  one  may  easily  poison  another  by 
a,  combustion  conversion  complete;  b,  lesser  affinities  existing 
between  toxicant  and  the  molecules. 

The  life  of  the  cell  depends  upon  the  absence  of  these  dele- 
terious molecules  for  which  there  are  affinities  precisely  as 
there  is  necessity  for  somatic  absence  from  fire.  Prussic  acid 
presents  the  simplest  example.  The  nitrogen  therein  is  in  a 
dangerously  assimilable  form,  and  its  sudden  surcharging  of 
the  nerve-centers  with  carbonized  blood  paralyzes  the  body. 

Herbert  Spencer  f  elaborates  the  anaesthetics'  modes  of  ac- 
tion. No  philosophy  can  explain  nerve  action  by  excluding 
nerve  and  nerve-center  therapeutics.  As  certain  drugs  have 
specific  affinities  for  certain  groups  of  nerves,  it  follows  that 
the  times  of  action  of  such  groups  differ  from  others,  and  in 
such  selective  affinities  we  have  indications  of  the  differential 
molecular  workings  of  both  nerves  and  neurotics.  If  the  cell 
becomes  adapted  to  a  certain  environment,  and  the  genus  of  a 

*  Origin  of  Species,  p.  18. 
f  Principles  of  Psychology. 


CLEVENGER — Physiology  and  Psychology.  167 

certain  chemical  combination  be  poisonous,  one  species  of  such 
genus  may  through  adaptation  cease  to  be  a  poison  within 
relatively  restricted  limits.  A  readjustment  of  the  entire  body 
may  occur  permanently  for  the  race  or  for  the  individual  on 
the  basis  of  toleration.  For  instance,  phosphorus  has  been 
adopted  as  a  normal  ingredient  of  cerebral  tissue  ;  but  antimony 
and  arsenic  in  the  same  group  remain  as  poisonous  as  phos- 
phorus is  to  those  animals  whose  assimilative  adjustment  for  it 
has  not  reached  the  stage  it  has  in  man. 

On  the  principle  that  a  millionth  of  an  inch  is  as  much  of  an 
entity  as  is  a  million  miles,  molecular  distances,  though  unseen 
and  unmeasurable,  inferentially  exist  The  vast  range  of  tis- 
sue solidities  throughout  the  body,  the  coarseness  of  the  del- 
toid muscle,  and  structural  fineness  of  other  muscles,  the 
varying  permeability  of  organs  and  their  ability  or  inability  to 
resist  molar  or  molecular  motions  of  graded  degrees,  the 
adjusted  calibers  of  vessels  to  their  contents,  of  cell  and  cell 
granules  aggregation  in  dermis,  epidermis,  lung,  liver,  serous 
membrane,  and  bone,  like  the  callous  palm  of  the  laborer,  or 
the  bicipital  growth  of  the  oarsman,  indicate  the  adjustment 
of  molecular  distances  to  the  exercise  they  undergo.  In  iron 
wire  the  passage  of  so  imponderable  an  influence  as  electricity 
in  one  direction  adjusts  the  atomic  distances  in  lines  of  least 
resistance.  This  is  so  well  known  to  electricians  that  telegraph 
companies  often  order  their  current  directions  reversed  to  ha- 
bituate the  flow  to  indifferent  directions.  Analogy  forbids  any 
other  view  than  that  nerve  tissue  is  no  exception  to  this  law  of 
adjustability,  and  that  constant  causes  produce  constant  effects 
in  creating  densities  of  nerve  structure  consonant  with  the 
work  performed.  The  softness  of  the  " portio  mollis"  the 
hardness  of  the  other  nerves,  notably  the  optic,  are  signifi- 
cant and  seem  related  to  the  differences  *in  wave  length 


1 68  CLEVENGER — Physiology  and  Psychology. 

conveyance.  Roughly  estimating  the  comparative  densi- 
ties of  the  auditory  and  optic  as  I  to  10,  the  former  related  to 
vibrations  of  from  40  to  4xio4,  the  approximate  equation  is 
obtained  ^Jjf2  =  1 8925x1  o6  for  the  retardation  which  the 
highest  light  ray,  violet,  must  undergo  in  comparison  to  that 
of  the  highest  note  that  is  heard.  The  assumed  greater  den- 
sity 10  of  the  optic  nerve  dropping  the  ratio  only  one 
power  =  1 8925x1  o5,  and  even  were  the  optic  one  hundred 
times  denser,  the  whole  differences  would  not  suffice  to  ac- 
count for  the  transformation  undergone  except  by  calling  in 
the  peripheral  apparatus  and  its  rhodopsin.  Nevertheless  it  is 
evident  that  the  centripetal  differences  create  some  changes  in 
densities. 

Stieda  calls  attention  to  the  axis  cylinders  of  the  second  root 
of  the  auditory  nerve  as  thicker  than  that  of  any  other,  the 
first  having  delicate  fibrils.  The  second  has  a  ganglion  upon 
it  like  the  intervertebral.  What  these  changes  in  destiny 
measure,  and  the  precise  molar  and  molecular  arrangements 
may  be,  are,  at  present,  only  conjecturable,  but  their  existence 
is  beyond  dispute. 

The  celebrated  Chladni  figures,  made  by  the  action  of  musi- 
cal vibrations  upon  sand  arranged  on  glass  plates  or  mem- 
branes, as  yet  have  not  had  the  causes  of  their  appearances  be- 
ing related  to  their  corresponding  notes  discovered,  but  the 
rule  is,  that  to  a  determinate  note  belongs  a  determinate  figure 
for  the  same  membrane  or  plate,  and  that  a  figure  is  more  com- 
plicated as  the  note  producing  it  is  higher. 

The  only  observable  aspect  of  these  figures  in  the  nerves  is 
density,  and  here  we  must  not  mistake  gross  appearances  for 
intrinsic  differences,  for  connective  tissue  increase  may  sclerose. 
I  refer  to  the  densities  of  the  intimate  proper  nerve  substance 
which  cannot  always  be  inferred  from  simple  inspection.  The 


CLEVENGER — Physiology  and  Psychology.  169 

presence  or  absence  of  water,  fatty  matter,  protoplasmic  soft 
substance,  etc.,  with  the  distances  apart  of  granules  and 
the  intimate  density  of  the  granules  themselves,  present  a  com- 
plex upon  which  impinging  forces  would  act  to  arrange, 
mould,  adjust,  and  rearrange. 

Now,  the  persistency  of  a  force,  its  frequent  recurrence,  could 
not  do  otherwise  than  produce  a  definite  arrangement,  inter- 
molecular,  intergranular,  and  with  regard  to  extrinsic  but  as- 
sociated elements.  We  are  forced  to  speak  of  the  arrangement 
of  a  nerve  as  including  its  density  and  the  other  factors  men- 
tioned. 

A  telephone  and  its  wire  used  for  years  in  a  mine,  to  ac- 
quaint the  engineer  above  ground  with  the  workings  of  the 
valves  in  the  pumps  below,  was  found  to  have  so  adapted  it- 
self to  the  almost  uniform  vibrations  as  to  give  other  sounds 
imperfectly. 

A  nerve  which  has  undergone  adjustment  acts  reflexly 
instinctively,  and  where  not  only  in  the  individual  but  in  the 
species,  impressions  constantly  recur,  the  nerve  arrangement 
would  be  inherited.  Impressions  common  through  long  pe- 
riods to  all  animals  would  arrange  common  nerves  in  common 
manners.  Impressions  only  experienced  by  a  species  or  race 
would  differentiate  nerve  structure  therein  above  the  common, 
provided  the  recurrence  of  the  impressions  were  frequent. 

Impressions  only  experienced  by  an  individual  result  in  a 
reintegration  of  the  nervous  system  at  the  expense  of  disinte- 
gration of  racial  and  species  adjustment,  and  such  breaking  up 
of  inherited  arrangements  we  know  to  be  exceedingly  difficult 
to  bring  about. 

The  more  perfect  adjustment  of  nerve  elements  to  the  trans- 
mission of  vibrations  constitute  instinct,  and  I  extend  this 
facility  of  motion  to  sensation,  feeling,  motor  muscular  activity, 
and  to  all  mental  processes. 


1 70  CLEVENGER — Physiology  and  Psychology. 


CHAPTER   X. 

MENTAL  PHYSICS. 

Reason  or  deliberation,  or  in  the  spinal  nerve  action,  hesi- 
tancy in  reflex  response  is  indicative  of  resistance  to  the  pas- 
sage of  a  new  set  of  impressions,  the  inharmony  of  the  adjust- 
ment to  the  influence  causing  the  deliberation.  As  soon  as 
the  vibratile  term  most  in  accord  with  the  impression  has  been 
determined  upon,  the  action  which  follows  is  the  effect  of  most 
accordant  routes  having  been  selected.* 

Hammond's  dictum,  that  where  there  is  gray  matter  there 
is  mind,  could  be  extended  to  nerves,  thence  to  muscles, 
thence  to  protoplasm.  Mind  is  a  thing  of  such  degrees  that 
from  its  evolution  in  man  to  its  beginning  differentation  in  the 
protozoon  we  can  no  more  demarcate  the  steps  of  its  growth 
than  we  can  tell  where  the  seed  ceases  to  be  a  seed  and  be- 
comes a  tree.  Huxley's  comparison  of  the  mind  to  the  horo- 
logity  of  the  clock  is  a  just  one.  Stop  the  pendulum,  or  de- 
range the  mechanism  otherwise,  and  the  time-keeping  capacity 
of  the  clock  is  in  abeyance.  Interference  with  any  of  the  liv- 
ing cells  in  the  body,  according  to  their  states  of  mental  inte- 
gration and  relationship,  will  derange  the  nervous  and  mental 
mechanism  and  its  life-subserving  workings,  the  mind. 

Cope  assigns  mind  to  the  protoplasmic  cell ;  so  do  I,  but 
in  the  sense  of  mind  being  only  on  a  par  with  all  the  other 
chemical  and  mechanical  motions  of  the  body.  It  is  in  the 

*  Further  elaborated  in  my  "Contributions  to  Comparative  Psychology," 
Science  (N.  Y.).  "Instinct  and  Reason,"  May  28th,  1881.  "Origin  of  Lan- 
guage," July  23d,  1881. 


CLEVENGER — Physiology  and  Psychology.  171 

metazoa  the  coordinated  activities  of  the  associated  cells,  of 
every  cell  in  the  animal,  regardless  of  development,  shape,  size, 
location,  or  degree  of  vitality.  As  Spencer  claims,  it  is  insep- 
erable  from  other  vital  workings. 

As  in  the  amceba  there  cannot  be  movement  without  mo- 
lecular consumption,  nor  repetition  of  this  movement  without 
re-supply  throughout  animal  life,  we  see  the  ability  of  tissues 
to  maintain  their  integrated  arrangement  and  yet  to  be  subject 
to  waste  and  repair.  This  nutrient  possibility  of  maintaining 
the  adjustment,  once  fastened  upon  the  organism,  cannot  be 
denied  to  nerves ;  the  gross  muscular  and  other  persistencies 
imply  molecular  arrangement  persistence  in  the  face  of  de- 
struction. When  in  the  organization  of  the  metazoa  definite 
organs  as  cilia  appear,  adaptation  to  repetition  of  movement  is 
apparent  and  each  cilium  will,  in  repeating  a  movement,  cause 
a  repetition  of  associated  molecular  motions  in  its  sarcode 
directly  related  to  these  motions.  Now,  if  with  the  first  repeti- 
tion of  that  ciliary  motion  we  grant  that  similar  molecular 
movements  to  the  initial  motion  were  reproduced,  then  we 
have  the  necessary  conception  of  memory.  Let  the  ciliary 
motions  and  the  accompanying  molecular  sarcodal  changes 
continue  indefinitely,  memory  becomes  merged  into  hard  and 
fast  lines  of  energy  capabilities,  definite  molecular  transloca- 
tions,  and  so  far  as  an  animal  can  or  cannot  be  said  to  remem- 
ber an  act  which  is  part  of  its  existence  and  of  momentary  re- 
currence, it  is  conceivable  that  it  would  require  a  decided 
disturbance  of  its  structure  to  cause  it  to  forget.  But  as 
Ribot*  points  out,  we  remember  by  forgetting,  and  it  is 
through  rendering  the  reflex  susceptibilities  to  recurring  stim- 
uli automatic  and  part  and  parcel  of  our  structure  that  we  are 
enabled  to  integrate  this  kind  of  memory  with  instinctive  mo- 
tion and  cease  to  regard  it  till  disturbance  occurs. 
*  Les  Maladies  de  la  Memoire. 


172  CLEVENGER — Physiology  and  Psychology. 

An  associated  molecular  change  which  faintly  disturbs  the 
protoplasmic  granules  concerned  in  the  ciliary  motions  will 
thus  revive  the  memory  of  those  movements.  Let  an  internal 
fortuitous  agitation '  of  a  sleeping  hungry  amoeba  take  place, 
instantly  the  impression,  the  memory  of  eating  is  revived, 
through  molecular  changes  induced  identical  with  what  occurs 
in  eating,  and  may  provoke  appropriate  grosser  movements, 
such  as  protrusion  of  pseudopodia.  This  similarly,  though 
with  basal  identity,  occurs  in  the  dreams  of  a  hungry  man. 
The  irritations  from  the  viscera  produce  a  tension  of  the  gas- 
tric and  intestinal  distribution  of  nerves  requiring  but  the 
faintest  correlative  irritation  from  the  brain  to  suggest  the 
feast. 

In  the  diaphragm  to  diaphragm  telephonic  transmissions  of 
waves,  the  plexus  of  diaphragmatic  vibrations  oscillate  in 
changed  terms  along  the  wire,  to  be  revived  at  the  other  end. 
It  is  not  necessary  to  have  termini  alike  in  the  case  of  nerves, 
for  whatever  the  initial  oscillations  may  be,  their  translation 
into  neural  movements  suffices  to  revive  memory  of  similar 
movements,  adjusted  to  in  the  cord  and  brain. 

Conceive  now  of  an  associated  apparatus,  by  which  the  tele- 
phone line,  which  we  must  regard  as  adjusted  to  definite  waves, 
has  its  oscillations  revived  independently  of  the  usual  end 
apparatus.  If  these  otherwise  induced  groups  of  waves  be 
identical  with  those  produced  in  the  ordinary  way,  then  the 
diaphragm  vibrations  will  be  as  definite  as  though  ordinarily 
induced.  The  phonograph  traces  its  characters  upon  a  metal 
sheet,  and  through  them  the  sounds  which  produced  them  may 
be  recalled.  It  matters  nothing  how  these  wire  vibrations 
which  make  both  character  and  sound  are  generated,  if  any 
other  influence,  similar  to  that  which  we  know  is  at  work  upon 
nerve  tissue,  produces  identical  waves,  however  feebly,  both  or 


CLEVENGER — Physiology  and  Psychology.  173 

either  characters  and  sounds  may  be  made.  This  is  intended 
to  represent  revivification  of  memory  through  association,  such, 
for  instance,  as  occurs  in  recalling  the  odor  of  a  rose  when  an 
image  of  a  rose  is  aroused  in  the  mind. 

The  integrity  of  related  organs,  at  least  for  a  definite  time, 
is  essential  to  memory.  For  example,  the  joints  in  arthropodal 
members,  and  in  metazoa  generally,  differentiate  limb  move- 
ments which  adjust  the  muscular  protoplasmic  and  nerve  ar- 
rangements after  repetition,  and  thus  memory,  in  common  with 
other  attributes  of  mind,  is  an  osseous  and  a  muscular  as  well  as 
a  nervous  phenomenon. 

It  is  well  known  that  convulsions  so  adjust  the  nervous  sys- 
tem as  to  make  their  recurrence  easier. 

Delbceuf  *  adopts  a  view  of  molecular  adjustment  as  consti- 
tuting memory ,but  does  not  make  applications  such  as  are  found 
herein.  Doubtless  many  other  suggestions  I  have  made  herein 
have  been  advocated  before,  but  their  synthetical  arrangement 
I  shall  claim,  together  with  such  matters  as  the  nutrient 
reflex,  as  original.  It  was  at  a  recent  date  fashionable  to  ascribe 
everthing  to  Aristotle.  He  was  even  accredited  with  suggesting 
the  rotundity  of  the  earth,  but  it  was  not  mentioned  that  he, 
in  the  next  breath,  advanced  reasons  against  such  an  idea. 

Wundt,  Spencer,  and  Bain  are  each  close  to  the  truth  in  their 
several  psychologies,  but  it  is  only  by  elimination  of  error  and 
adjusting  with  reference  to  extensive  ranges  of  facts,  that  com- 
plete consistency  will  be  evolved  in  such  matters. 

To  read  of  memory,  as  described  by  many  writers,  one 
would  suppose  it  infallibly  reproduced  facts  and  images;  but 
it  does  not,  it  is  treacherous  in  the  extreme,  and  only  when 
cultivated  is  it  free  from  gross  error.  In  hyperaesthetic  states 
it  may  reproduce  minutiae,  nor  is  this  to  be  wondered  at  when 
we  grant  it  ability  to  recall  anything.  In  the  main  it  is  illusory, 
and  made  up  of  all  sorts  of  superimposed  experiences.  The 

*Th6orie  G6n6rale  de  la  Sensibility,  p.  60. 


1 74  CLEVENGER — Physiology  and  Psychology. 

limner  takes  advantage  of  the  readiness  of  the  memory  to  sup- 
ply omitted  points  when  he,  with  a  few  lines,  leads  you  to 
imagine  you  have  seen  details  he  did  not  fill  in  his  sketch. 

Memory  is  an  important  intellectual  omnibus,  and,  as  Ribot 
says,  consists  of  memories,  which  accounts  for  the  loss  of  abil- 
ity to  recall  certain  things  only.  I  would  like  to  epitomize 
Ribot's  excellent  work  in  this  connection,  but  want  of  space 
forbids.  The  inability  to  recall  the  letter  F,  in  the  case  he 
cites,  shows  how  memorized  coordinations  of  muscles  may 
be  ineffectual  through  stimuli  failing  to  act  upon  a  defunct 
center  for  such  coordination.  Harrison  Allen's  recently  in- 
vented "palate  myograph"*  would  be  valuable  as  an  aid  in 
determining  the  muscles  involved,  and  inferentially  afford 
knowledge  of  the  coordinations  of  articulation. 

The  patient  recorded  by  Dr.  Ball,f  who  could  not  speak 
certain  words  he  could  not  hear,  had  lost  hearing  memory  of 
words,  and  could  not  pronounce  them  for  want  of  the  usual 
stimuli  to  such  coordinations.  Finkelburg's  J  suggestion  of 
asymbolia  for  all  phenomena  of  aphasia  is  a  good  one,  as  it 
generically  classifies  these  failures  of  speech  and  gesture. 

I  think,  since  Exner's  researches  have  given  us  better  de- 
fined notions  of  a  modified  localization  in  the  cerebrum,  that 
the  word  registration  (of  which  Spitzka  is  so  fond)  expresses 
the  function  of  the  adjustment  or  arrangement  I  have  at- 
tempted to  elaborate. 

The  registration  is  simply  the  facile  possibility  of  revivifica- 
tion of  the  oscillations  within  the  limits  of  nerve-arrangement 
and  revivification  of  such  registered  impressions  is  a  memory. 

Memory  in  sensation  has  its  analogue  in  the  motor  appara- 
tus and  motor  incoordination,  or  erratic  reflexes  may  be  the 

*  American  Naturalist,  April,  1884,  p.  38. 

f  Archives  of  Medicine,  April,  1881. 

J  Berliner  Klin.  Woch.,  1870,  Nos.  37,  38. 


CLEVENGER — Physiology  and  Psychology.  1 7  5 

congener  of  amnesia.    Kussmaul*  regards  this  motor  memory 
as  necessary  to  an  explanation  of  aphasia. 

Partial  amnesia  will  be  caused  by  disarrangements  of  certain 
tracts. 

Temporary  amnesia,  their  temporary  failure  of  adjustment. 

Periodic  amnesia,  also  temporary,  but  recurrent,  due,  doubt- 
less, to  a  nutritive  failure. 

Progressive  amnesia,  as  in  senility,  the  permanent  involu- 
tional  change  which,  being  disintegrative,  resists  rearrange- 
ments, at  least  of  a  permanent  character.  The  progress  is  from 
forgetting  proper  nouns  to  common,  thence  to  adjectives  and 
verbs,  and  finally  emotional  language  and  gesture,  from  the 
less  to  the  better  organized,  from  the  complex  to  the  simple. 

Exaltation  of  memory  would  follow  hyperaesthesia  or  raise 
of  plane,  and  in  some  mania  cases  both  the  sensory  and  motor 
memories  are  much  exalted. 

Kussmaul's  "Bewegungsbilder"  suggests  motor  as  well  as 
sensory  registration  in  the  brain  and  nerves. 

The  brain,  and  particularly  the  gray  matter,  receives  an 
enormous  amount  of  blood.  In  no  other  part  of  the  body  is 
the  nutritive  function  so  active  or  so  rapid.  The  stability  of 
modifications  and  the  dynamic  associations  between  nerve  ele- 
ments can  only  be  produced  by  nutrition  (Ribot,  op.  cit.). 

Between  nutrition  and  retention  there  is  a  cause  and  effect 
relationship. 

The  slide-valve  cut-off  for  steam  cylinders  is  an  arrangement 
in  sequence,  and  its  action  may  be  likened  to  that  motion  of 
muscles  which,  reaching  a  certain  point,  is  followed  by  re- 
lated movements  of  other  muscles.  Certain  acquired  motor 
memories  being  invoked,  are  followed  by  associate  memories 
for  other  motor  apparatus.  This  acquisition  is  similar  to  the 
sensory  association  phenomenon  of  learning  a  thing  by  its  con- 

*  Die  Siorungen  der  Sprache. 


176  CLEVENGER — Physiology  and  Psychology. 

nection  with  some  attendant  thing  or  circumstance.  One  re- 
vived impression  is  apt  to  call  up  another.  Does  this  require  a 
special  association  apparatus  or  a  molecular  motion  relationship 
of  the  sensory  and  motor  events  ?  We  know  that  the  first  exists 
and  is  developed  pari  passu  with  association  powers,  but  how 
is  association  effected?  Having  the  machinery,  how  does  it 
act  ?  The  fibrillae  cross  and  re-cross  each  other,  abutting  in 
gray  centers  and  among  nerve-cells  without  decided  connec- 
tions with  each  other  or  with  the  main  strands.  The  resultants 
of  interference  vibrations  or  musical  beats  are  suggestive,  but 
insufficient,  for  beats  cannot  revive  the  notes  from  which  they 
were  derived.  The  arrangements  of  both  fibrils  and  nerves 
suggest  diffusion,  and  diffusion  it  seems  to  be,  with  the  reserva- 
tion that,  when  association  by  diffusion  becomes  definite  be- 
tween impressions  or  motions,  tracts  are  built  up  through  use. 
The  lines  of  least  resistance  are  the  lines  associating  memories 
or  other  faculties,  and  in  the  cord  those  lines  are  in  contiguous 
levels,  the  network  of  Gerlach,  and  for  higher  and  lower  levels 
the  white  columns  of  the  cord.  Diffusion  having  built  up 
these  tracts,  the  sensations  and  motions  are  correlated  by  lines 
which  vibrate  in  unison  with  the  tracts  they  connect,  so  that 
forces  from  one  tract  may  pass  over  the  commissure  and 
arouse  the  vibrations  of  the  other  tract  feebly  or  strongly. 
Commissural  fibers  then  are  capable  of  conveying  two  or  more 
rates  common  to  other  fibers  with  which  they  are  associated. 
Coordinated  movements  must  have  fibers  capable  of  being 
simultaneously  and  successively  vibrated  through  uniting 
fibrils  in  which  vibratory  movements  simultaneously  and  suc- 
cessively pass  which  are  common  to  the  main  nerves  stimu- 
lated. It  is  not  necessary  that  each  two  nerves  should  have 
a  definite  association  system,  notwithstanding  the  millions  of 
commissural  fibers  that  exist. 


CLEVENGER — Physiology  and  Psychology.  177 

It  suffices  alone  that  an  impression  should  in  the  faintest 
degree  resemble  some  previous  impression  to  revive  associated 
memory. 

Given  two  simultaneous  impressions,  optic  and  auditory,  the 
former  abutting  in  the  gyrus  cuneus,  and  the  latter  in  the 
supra-marginal  gyrus,  the  coordination  of  these  impressions 
would  be  effected  by  any  preexisting  tracts.  Such  tracts, 
upon  incessant  stimulation,  could  undergo  better  definition, 
and  this  would  seem  to  involve,  not  only  the  building-up  of 
the  callosum,  but  of  definite  cortical  striae  formations,  such  as 
a  priori  one  would  expect  to  find  relating  the  "visual"  sense 
(in  man  the  most  important)  with  senses  or  motions  the  most 
frequently  occurring. 

It  may  not  be  necessary  that  the  uniting  fibrils  should  have 
the  tension  strength  of  the  united  fibrils.  We  may  surmise, 
from  the  small  work  of  network-fibril  sizes,  that  it  suffices  if 
the  uniting  fibril  acts  at  all,  in  which  case  the  memory  latent 
in  each  main  fibril  will  be  evoked  or  stimulated  when  the 
other  two  parts  act.  The  most  important  thing  to  remember 
is  that  the  nutrient  reflex  occurs  with  every  cerebro-spinal  irri- 
tation, the  vaso-motor  flash  of  supply  to  the  points  irritated. 
This  seems  to  be  the  "  something  else,"  the  tertium  quid,  for 
which  psychologists  have  sought.  The  auditory  and  optic 
centers  being  stimulated,  their  respective  blood-supplies  are 
reflexly  stimulated  with  an  increasing  disposition  to  nourish 
an  intermediate  tract,  or  to  arrange  more  definitely  the  fibrils 
over  which  the  association  is  made,  the  stimulation  of  one 
sense  sufficing  to  produce  faint  vibrations  of  the  other. 

Motor  memories  are  thus  evoked,  and  both  successive  and 
simultaneous  motor  coordinations  effected.     The  same  plexus 
of  fibrils  answer  for  association  of  sensory  and  motor  recur- 
rences. 
12 


1/8  CLEVENGER — Physiology  and  Psychology. 

The  agreement  of  this  hypothesis  with  the  structural  facts 
of  the  brain  are,  to  me,  very  convincing. 

"According  to  Meynert,  the  role  of  the  cortex  is  not  so 
much  the  liberation  of  motive  force  as  the  mediation  of  sensa- 
tions of  innervation  (Inneruationsgefuhle).  All  determinable 
function  areas  which  on  physiological  grounds  must  be  con- 
sidered to  require  a  bond  of  association  are  found  to  present 
regional  points  of  contact.  Thus  the  symbolic  field  (for  writ- 
ten and  spoken  symbols)  approaches  the  fields  of  the  upper  ex- 
tremity of  the  tongue  and  of  hearing."* 

Munk  and  Exner  call  attention  to  the  tactile  areas  of  the 
cortex  being  topographically  identical  with  the  motor  centers 
of  the  corresponding  periphery, 

11  Perception  reaches  the  maximum  of  clearness  in  attention" 
well  says  Guiseppe  Surgi.f 

"We  hear  best  in  breathless  attention,"  remarks  Tuke.J  A 
theory  of  perception  thus  would  best  be  considered  through  an- 
alyzing attention. 

According  to  my  suggestion  of  nutrient  reflexes,  the  increase 
of  centric  irritation  would  produce  an  afflux  of  blood  to  the 
part  in  functional  activity.  The  blood  is  there  because  of  the 
work  being  done  there,  just  as  friction  calls  blood  to  the  skin. 
Listening  to  a  sound,  the  sight  is  not  so  acute.  Interferences 
between  recollections  or  acute  perception  of  impressions  are 
less  when  they  relate  to  different  senses  than  when  they  are 
terms  of  one  sense.  A  landscape  and  piece  of  music  may  be 
enjoyed  simultaneously,  but  not  two  sights  or  two  kinds  of 
auditory  impressions.  In  "  breathless  attention  "  the  nutrient 
reflex  not  only  affords  one  center  an  extra  supply  of  blood  for 
its  activity,  but  denudes  other  centers,  even  the  pneumogastric, 

*Spitzka's   Review  of  Exner's   Pathol.    Researches.     Journal  of  Neurology 
and  Psychiatry,  Vol.  i.,  No.  2. 

f  Teoria  fisiologica  della  Percezione,  1881. 
J  Influence  of  the  Mind  upon  the  Body,  1884. 


CLEVENGER — Physiology  and  Psychology.  179 

to  a  minimal  supply.  Faintness  from  an  overpowering  emo- 
tion or  impression  may  thus  be  caused. 

In  expectant  attention,  the  nutrient  reflex  anticipates  the 
activity,  and  the  "dilemma  period"  is  shortened,  and  more  so 
if  the  thing  to  be  seen,  as  a  red  color,  is  denoted  beforehand. 
Memory  recalls  the  red  color,  and  the  optic  area  is  better  sup- 
plied with  blood,  while  adjacent  areas  are  inhibited  vaso- 
motorially. 

Thus,  in  perception  and  attention,  the  vaso-motors  are  con- 
cerned largely. 

Sir  Henry  Holland  notes  epistaxis  increased  by  attention, 
and  John  Hunter  was  able  to  produce  a  sensation  in  a  part  by 
fixing  his  attention  upon  it.  Unzer  says  :  "  Expectation  of 
the  action  of  the  remedy  often  causes  its  operation  before- 
hand." All  these  are  connected  with  vascular  changes.  In 
some,  this  ability  to  recall  a  peripheral  sensation  is  accompa- 
nied with  increase  of  blood-supply  and  heat  in  the  part,  an- 
other vaso-motor  reflex  produced  by  cerebro-spinal  centrifugal 
irritation.  I  regard  this  as  more  an  unconscious  motor  phe- 
nomenon, the  sensation  and  vaso-motor  act  being  secondary. 
Maury,  quoted  by  Tuke,  refers  stigmatization  to  a  similar 
cause. 


i8o  CLEVENGER — Physiology  and  Psychology. 


CHAPTER.    XL 

MORPHOLOGY,  HISTOLOGY    AND    EVOLUTION  OF  THE   HUMAN 

BRAIN. 

In  several  articles,  published  in  scientific  and  medical  jour- 
nals,* I  advanced  and  maintained  what  is  known  as  the  inter- 
vertebral  homology.  The  fact  of  its  having  originated  in 
America  has  delayed  its  general  notoriety,  as  semi-scientific 
men  on  this  side  of  the  Atlantic  prefer,  as  a  rule,  to  credit  start- 
ling things  to  our  transatlantic  pundits,  or  at  least  to  postpone 
notice  of  American  ideas  until  forced  to  acknowledge  their 
value.  It  is  the  same  spirit  which,  among  the  less  intelligent, 
affords  the  "  dudesque  "  Anglomania. 

The  simplest  spinal  cord  is  owned  by  the  amphioxus,  a  form 


lower  than  the  lamprey  eel.  This  fish-like  animal  has  no> 
brain.  Extended  the  length  of  the  body  is  the  cord,  and 
nerves  enter  it  dorsally  and  ventrally ;  the  second  pair  of  nerves 
at  the  head  end,  (Fig.  23)  pass  caudally,  according  to  Owen, 
but  Huxley  does  not  describe  them  as  so  doing.  They  merely 

*  Journal  of  Nervous  and  Mental  Disease,  October,  1879,  "Ceiebral  To- 
pography; "  April,  1880,  "  The  Sulcus  of  Rolando  and  Intelligence  ;  "  October, 
1880,  "  Plan  of  the  Cerebro-Spinal  Nervous  System."  American  Naturalist  y 
January  and  February,  1881,  "Comparative  Neurology;"  July,  1881,  "Origin 
and  Descent  of  the  Human  Brain."  Chicago  Medical  Journal  and  Examiner, 
November,  1880,  "Cerebral  Anatomy  Simplified." 


CLEVENGER — PJiysiology  and  Psychology. 


181 


appear  to  be  slightly  more  complex  in  their  anterior  distri- 
butions. Those  uppermost  in  the  diagram  are,  along  the  back, 
sensory  nerves,  the  lowermost  being  motor. 

The  cord  of  the  lamprey  (Petromyson  fluviatilis)  is  quite 
rudimentary,  but  a  distinct  brain  presents  itself  in  this  case  for 
analysis.  We  find  certain  intumescences  at  the  head  end 
which  can  be  represented  schematically  thus : 


The  real  appearance  of  these  g'anglionic  swellings,  for  such 
they  are,  resembles  the  embryonic  fusion  of  cerebral  and  spinal 
ganglia.  Notice  that  in  this  low  vertebrate  form  these  enlarge- 
ments of  the  sensory  or  ingoing  nerves  occur  at  the  head. 

A  teliost  fish,  the  Trigla  Adriatica,  affords  an  example  of 
these  same  enlargements  appearing  all  along  the  spinal  column : 


I  ill 


i      i      i 

000 


The  lateral  fusion  also  between  these  ganglia  in  the  head 
end,  occurs  among  the  intervertebral  in  Orthagonscus  mola. 

Taking  a  general  survey  of  the  piscine  and  amphibian  brains, 
we  find,  in  many,  these  ganglia  well  defined  as  rounded,  sym- 
metrically placed  bodies  (lepidosteus,  amblyopsis,  leuciscus), 
while  in  others,  these  lobes  are  distorted  by  elongation  or 
cramping  in  all  directions  (sturgeon,  sharks,  chimaera),  and  in 
still  others,  some  of  the  lobes  are  pushed  below  the  usual  site 
(cod,  herring,  perch).  Of  necessity,  the  ventricles  must  often 


1 82  CLEVENGER — Physiology  and  Psychology. 

be  partially  or  wholly  obliterated,  showing  the  inexpediency 
of  making  use  of  ventricular  passages  in  homologizing. 

This  crowding  together,  fusion  and  distortion  of  ganglionic 
lobes,  obtains  throughout  animal  life,  and  the  olfactory  lobe  is 
often  so  closely  fused  with  the  prosencephalon  as  to  afford  us 
no  line  of  separation.  The  corpora  bigemina,  which  lie  upon 
the  upper  surface  of  the  brain  in  reptiles,  are  succeeded  in 
birds  by  these  bodies  being  thrown  down  to  the  sides  and  base 
of  the  brain,  crowded  there  by  the  greater  relative  size  of  the 
superior  lobes. 

The  intervertebral  ganglia  which  develop  on  the  afferent 
nerves  of  the  higher  vertebrates  undergo  great  development 
within  the  cranium,  and  by  lateral  crowding  together  the  me- 
dian line  of  separation  is  obliterated,  giving  us  the  large  cen- 
tral lobe  of  the  shark  and  birds.  Two  or  more  of  these  ganglia, 
as  was  noted  by  Davida,  may  develop  upon  the  same  sensory 
strand.  The  subsequent  lateral  lobes  of  the  cerebellum  can  be 
resolved  either  into  secondary  or  primary  ganglia,  or  a  mix- 
ture of  both,  certainly  the  vagus  tubercle  of  the  fox  shark  is 
in  all  essentials  the  pneumogastric  lobule  of  man's  cerebellum, 
the  flocculus. 

Thus  it  appears  that  by  the  pressure  together  of  a  number 
of  these  posterior  root  swellings  a  cerebellum  has  been  formed. 
The  cerebellum  is  now  generally  conceded  to  be  a  coordinator 
of  sensation  for  cranial  sensory  nerves,  and  how  can  it  be  other- 
wise from  this  view?  By  this  coalescence  of  intervertebral  bodies 
it  follows  that  sensations  passing  in  from  a  variety  of  points 
must  be  distributed  to  a  wider  area  of  central  points  in  the 
medulla  and  spinal  cord.  This  explains  why  injury  to  the 
lateral  lobes  may  occur  without  manifestation  of  the  lesion, 
and  why  a  disorder  of  the  central  part,  or  vermis,  produces  an 
altered  gait.  The  main  bundles  of  ingoing  nerves  are  gathered 


CLEVENGER — Physiology  and  Psychology.  1 83 

in  the  latter  region,  while  the  plexus  of  fibers  in  the  latteral 
lobes  afford  many  avenues  for  impulse  passage,  other  than 
those  injured  or  destroyed.  The  original  globular  appearance 
of  the  lobes  composing  the  cerebellum  may  be  well  made  out 
in  most  quadrupedal  forms,  but  as  we  pass  to  man  we  see  that 
these  lobes  have  become  compressed  into  lamina,1. 

All  tubercles  of  the  vertebrate  brain  fall  within  the  category 
of  the  intervertebral,  a  notable  instance  being  the  Gasserian 
ganglion.  Mr.  A.  Milnes  Marshall,*  in  an  article  "  On  the  de- 
velopment of  the  nerves  of  the  chick,"  shows  plainly  that 
the  olfactory  nerve  must  be  considered  homologous  with 
spinal  nerves,  for  it  is  similarly  developed  and  in  no  way  dif- 
fers from  a  spinal  nerve.  Nor  does  the  comparison  rest  here, 
for  the  lobe  (not  bulb)  of  the  mammalian  olfactory  may  be 
seen  to  be  developed  between  the  central  tubular  gray  and  the 
periphery,  just  as  is  an  intervertebral  ganglion.  As  to  internal 
structure,  the  law  of  differentiation  shows  that  subsequently 
acquired  differences  are  no  arguments  against  original  deriva- 
tion, for  what  can  be  more  unlike  than  bone  and  cartilage,  hand 
and  foot,  skull  and  vertebrae,  and  yet  one  is  a  developed  or 
differentiated  form  of  the  other. 

Thus  the  mammillary  eminences,  the  optic  and  post-optic 
lobes,  were  originally  intervertebral,  and  the  olivary  body  em- 
bedded in  the  spinal  gray  is  another,  related  particularly  to 
innervation  of  the  tongue.  It  is  large  in  the  parrot,  and  has 
relation  to  the  ability  of  that  bird  to  articulate.  But  the  most 
general  interest  centers  in  the  large  mass  of  nerve  fibers 
and  cells  called  the  cerebrum.  In  the  ornithorynchus  it  is 
smooth  and  simple  in  form.  The  beaver  has  an  unconvo- 
luted  brain,  which  also  shows  at  once  the  folly  of  at- 
taching psychological  importance  to  the  number  and  intri- 


*  Monthly  Microscopical  Journal  (London),  October,  1877. 


1 84  CLEVENGER — Physiology  and  Psychology. 

cacy  of  folds  in  animal  brains.  With  phrenology,  which  lo- 
cates bibativeness  in  the  mastoid  process  of  the  temporal  bone, 
and  amativeness  in  the  occipital  ridge,  the  convolutional  con- 
troversy must  die  out,  as  did  the  old  so-called  science  of  palm- 
istry which  read  one's  fate  and  fortune  in  the  skin  folds  of 
the  hand. 

The  most  noticeable  change  in  form,  as  we  pass  up  the  scale 
of  mammalian  life,  occurs  in  the  production  of  the  fissure  of 
Sylvius.  In  most  quadrupeds  the  olfactory  lobe  fills  up 
largely  the  anterior  part  of  the  cranium.  As  the  smelling 
sense  diminishes,  this  lobe  degenerates  to  a  mere  tract,  and  the 
frontal  lobe  of  the  brain  increases  in  size,  lifting  the  forehead 
into  a  vertical  plane.  The  medulla  oblongata  is  pushed  for- 
ward to  a  less  oblique  angle  with  the  front  of  the  brain  from 
lemuridae  to  chimpanzee  and  man;  the  frontal  lobe  pressure 
covers  the  cerebellum  with  the  backward  progress  of  the  occi- 
pital lobe  till  finally  the  occipital  forms  the  temporal  by  curl- 
ing under  and  forwards,  forming  the  Sylvian  fissure.  These 
stages  of  progress  are  evident  in  the  horse,  elephant  and  hu- 
man embryo.  Often,  in  idiots,  we  find  through  want  of  devel- 
opment of  this  frontal  lobe,  that  ossification  takes  place  in  a 
plane  inclined  at  an  angle  corresponding  with  that  of  lower 
animals,  and  the  cerebellum  is  uncovered.  This  is  an  adapta- 
tion of  the  skull  to  its  contents,  which,  however,  does  not  al- 
ways take  place. 

There  are  other  elements  at  work  to  cause  the  skull  to  de- 
develop  normally,  or  even  enlarge  it  abnormally,  as,  for 
example,  an  accumulation  of  water  in  the  ventricles  will  change 
the  relative  positions  of  the  cranial  bones  to  such  an  extent  as 
to  give  to  the  hydrocephalic  idiot  "the  front  of  Jove." 

While  the  ontogenetic  stages  of  development  resemble  strik- 
ingly the  forms  mentioned  by  Haeckel,  the  nervous  system  is 
not  apparent  in  the  embyo  until  we  reach  the  ninth  or  acranial 


CLEVENGER — Physiology  and  Psychology.  185 

stage,  after  this  the  cerebral  vesicles  rapidly  develop  and 
resemble  in  general  the  cyclostome  stage.  Just  as  the  sharks 
and  mud  fishes  possess  the  intervertebral  ganglion,  which  the 
hags  and  lampreys  have  not,  the  human  foetus,  subsequent  to 
the  shaping  of  the  cerebral  vesicles,  develops  the  posterior 
spinal  nerve  root  swellings.  From  this  point  upward  it  is  easy 
enough  to  observe  that,  like  the  condition  found  in  the  brains 
of  marsupial  adults,  the  cerebellum  is  at  first  uncovered,  then 
by  frontal  lobe  growth  the  temporal  lobe  is  formed,  as  in  man 
and  apes. 

The  human  brain,  like  everything  else  in  the  universe,  has 
been  evolved  from  a  simpler  condition,  and  by  a  study  of  the 
forms  through  which  the  cerebrum  has  passed  to  its  present 
complexity  in  man,  we  have  been  enabled  not  only  to  see  the 
reasons  for  changes  in  appearances,  but  to  simplify  our  meth- 
ods of  instructing  students.  I  believe,  with  Prof.  Burt  G. 
Wilder,  of  Cornell  University,  that  no  medical  student  should 
be  allowed  to  dissect  the  human  cadaver  until  he  has  previous- 
ly familiarized  himself  with  the  anatomy  of  the  cat.  If  pre- 
vious to  this,  even,  he  should  study  the  crayfish,  with  Huxley's 
recent  popular  work  on  that  crustacean  as  a  guide,  he  will  find 
that  he  not  only  has  removed  vast  difficulties  from  his  course 
of  study,  but  will  be  able  to  continue  through  life  an  acquaint- 
anceship with  anatomical  and  physiological  essentials,  of  which 
our  present  methods  of  teaching  enable  the  average  student  to 
retain  only  a  smattering,  however  industrious  and  earnest  he 
may  have  been.  In  short,  we  cannot  master  human  anatomy 
without  a  knowledge  of  comparative  anatomy. 

The  primitive  typical  form  of  the  mammalian  cerebrum  is 
as  simple  as  this  figure,  an  oblate  spheroid : 


1 86  CLEVENGER — Physiology  and  Psychology. 

In  some  fishes  and  birds  it  is  globular,  and  therefore  a  still 
simpler  form. 

Rotate  an  ellipse  about  its  shorter  axis,  and  then  cut  the 
figure  so  produced  into  halves  in  the  direction  of  its  long  axis, 
and  the  low  form  of  the  hemisphere  from  which  we  start  is 
obtained.  We.  have  now  a  flattened  surface  which  has  been 
created  by  the  two  right  and  left  lobes  pressing  against  each 
other  as  the  brain  grew  faster  than  the  skull.  In  some  fishes 
the  original  spherical  appearance  of  the  two  lobes  may  be 
seen.  The  fissure  which  separates  the  two  hemispheres  is 
called  the  Great  Longitudinal  Fissure ',  and  this  cleft  is  along 
the  inner  flattened  faces  of  the  hemispheres,  each  of  which 
surfaces  is  known  as  the  Median  Surface,  The  External  Sur- 
face is  the  outermost  and  uppermost  part.  The  Basilar 
Surface  is  simply  the  lowest  or  under  part  of  the  cerebrum. 

Draw  two  parallel  lines  lengthwise  upon  the  external  sur- 
face. These  lines  are  sulci,  or  little  fissures  produced  by  the 
folding  in  of  the  soft  brain  tissue,  as  it  develops  more  rapidily 
than  the  bones  of  the  skull  expand : 


o 


One  such  furrow  may  be  seen  on  the  hedgehog's  cerebrum, 
the  other  is  added  in  higher  animals.  But  at  the  same  time 
there  appears  another  lobe  growing  in  front  of  this;  it  is 
the  frontal.  The  smallest  frontal  lobe,  speaking  relatively, 
is  owned  by  the  kangaroo,  and  adhering  to  our  schematic 
representation  is  shown  in  the  above  cut.  In  the  horse  we 
find  that  these  two  lobes  have  crowded  together,  the  frontal 
having  grown  much  larger,  but  the  original  line  of  junction 


CLEVENGER — Physiology  and  Psychology.  1 87 

between  the  two  is  still  evident  in  a  fissure  which  in  the  ele- 
phant, monkey  and  man  is  called  the  Sulcus  of  Rolando: 


r?    ) 


This  frontal  lobe  or  subsequent  growth  also  has  the  two 
longitudinal  cracks  in  the  highest  mammalia.  But  the  skull 
still  obstinately  maintains  its  rigidity,  lifting  a  little  on  top  as 
we  pass  up  the  scale  of  animals.  The  hemispheres  press 
back  over  the  cerebellum  only  at  this  stage  of  high  development ; 
previously  the  cerebellum  was  uncovered  by  the  cerebrum,  and 
now  another  change  begins.  As  the  frontal  lobe  continues  to 
grow,  it  crowds  the  occipital  part  back,  and  the  latter  cannot 
extend  in  the  same  direction  any  longer,  but  finds  room  below, 
in  the  posterior  part  of  the  skull,  whereupon  this  appearance 
is  presented : 


Where  the  posterior  lobe  folds  under,  the  temporal  lobe 
is  forming,  and  the  three  great  divisions  of  the  cerebrum  are 
more  evident — the  Frontal,  Occipital  and  Temporal  Lobes. 
The  first  two  are  separated  by  the  sulcus  of  Rolando,  the  last- 
named  from  the  occipital  by  the  large  fissure,  created  by  this 
folding-under  process — the  Fissure  of  Sylvius.  The  elephant's 
brain  exhibits  just  this  stage  of  development,  and  it  is  also  to 
be  seen  in  the  human  embryo. 

In  accomplished  development  the  scheme  of  the  cerebral 
fissures  and  sulci  of  man  would  be  thus  represented: 


1 88 


CLEVENGER — Physiology  and  Psychology. 


The  temporal   lobe  passing  forward  as  the  olfactory  lobe  of 
quadrupeds  diminishes  in  size  and  makes  room  for  it. 

But  by  gradual  filling  in  of  certain  portions  of  sulci,  breaks 
are  made  in  their  continuity  and  the  system  of  folds  is  ren- 
dered complex.  The  original  derivation,  however,  is  not  com- 
pletely masked,  for  we  may  still  trace  the  primitive  furrows 
into  the  fully  developed  cerebrum  of  man. 


The  convolutions  marked  I,  II,  III,  correspond  in  the  frontal 
lobe  to  those  marked  X,  IX,  VIII.  The  upper  posterior  con- 
volution VI  being  a  continuation  of  X,  while  the  point  c  of  the 
fissure  II  has  been  pushed  back  by  filling  in  of  the  space  an- 
terior to  it. 

The  deeper  furrows  are  known  as  fissures,  and  those  less 
deep  or  constant  as  sulci.  The  numbers  and  letters  in  the  fol- 
lowing list  correspond  with  those  of  the  figure  above : 

Convolutions  of  the  External  Surface. — I.  Superior  Frontal. 
II.  Middle  Frontal.  III.  Inferior  Frontal.  IV.  Ascending 
Frontal.  V.  Ascending  Parietal.  VI.  Superior  Parietal.  VII. 
Inferior  Parietal.  VIII.  Superior  Temporal.  IX.  Middle  Tem- 
poral. X.  Inferior  Temporal. 

The  fissures  and  sulci  of  the  external  surface  are:  2.  Fissure 
of  Sylvius.  6.  Sulcus  of  Rolando.  7.  Parietal  Sulcus.  8. 
Precentral  Sulcus.  9.  Superior  Frontal  Sulcus.  10.  Inferior 
Frontal  Sulcus.  n.  Superior  Temporal  Sulcus.  12.  Middle 


CLEVENGER — Physiology  and  Psychology.  189 

Temporal  Sulcus.  17.  Transverse  Occipital  Sulcus.  19.  In- 
ferior Longitudinal  Occipital  Sulcus. 

Small  parts  of  the  convolutions  conveniently  designated  Gyri 
are  known  as:  a.  the  operculum. (injury  to  which  causes  apha- 
sia), b.  Supra  marginal  gyrus.  c.  Angular  gyrus.  d.  First 
occipital  gyrus.  e.  Second  occipital  gyrus.  f.  Third  occipi- 
tal gyrus. 

The  median  surface  development  proceeds  in  animal  life  as 
fqllows:  With  the  advent  of  the  frontal  lobe,  its  inner  face 
fuses  with  the  occipital,  or  what  becomes  afterwards  the  parie- 
tal part  of  the  occipital,  on  a  line  which  divides  the  inner  sur- 
face just  as  the  sulcus  of  Rolando  divided  the  external  sur- 
face. 


But  the  corpus  callosum  appeared  in  forms  of  life  above  the 
marsupials  and  prevented  the  backward  extension  of  this  crack. 
It  had  to  pass  backward  over  the  corpus  callosum  thus : 


And  in  this  figure  we  see  the  corpus  callosum  (a  broad  band 
of  fibers  connecting  opposite  hemispheres  with  the  calloso- 
marginal  sulcus  just  above  it. 

As  the  hippocampus  major  was  curled  under  and  forward 
by  the  frontal  lobe  pressure,  the  rotation  of  it  and  the  fornix, 
together  with  the  resistance  of  the  skull  behind,  folded  in  the 
parieto-occipital  fissure,  which  in  monkeys  extends  across  the 
external  surface,  but  in  man  has  been  filled  in  upon  that  part: 


190 


CLEVENGER — Physiology  and  Psychology. 


When  the  calcar  avis  or  hippocampus  minor  developed  in 
the  ape's  brain,  another  fissure,  the  calcarine,  appeared  : 


The  fully  developed  Median  surface  of  the  cerebrum  is  rep- 
resented in  this  cut : 


Fissures  and  Sulci. — 6.  Termination  of  Sulcus  of  Rolando. 
1 6.  Callosso-marginal  Sulcus.  3.  Occipito-parietal  Sulcus. 
4.  Calcarine  Fissure.  5.  Hippocampal  Fissure.  14.  Collateral 
Sulcus. 

Convolutions  and  Gyri. — XI.  Marginal  Convolution.  XII. 
Fornix  Convolution.  XIII.  Cuneus  Convolution.  XIV.  Me- 
dian-Occipito-Temporal  Convolution,  g.  Uncinate  (or  hook) 
gyrus.  h.  Dentate  gyrus.  j.  Paracentral  gyrus  ( lesion  here 
always  causes  paralysis),  k.  Praecuneus  or  Quadrate  lobule. 
1.  Descending  gyrus. 

The  Cuneus  Convolution  (XIII),  has  recently  been  dis- 
covered to  be  an  "absolute"  center  for  sight  impressions. 
Injury  thereto  causing  optic  sense  derangements. 


CLEVENGER — Physiology  and  Psychology.  191 

This  last  cut  shows  the  convolutions  and    furrows  on  the 
Basilar  Surface : 


Some  of  these  parts  have  been  mentioned  under  the  heads 
of  other  surfaces,  as  they  may  appear  upon  two  surfaces. 
Those  most  clearly  basilar  are : 

Fissures  and  Suici. — 13.  Inferior  Temporal  Sulcus  (which 
is  an  extra  fold  in  the  human  brain,  due  to  the  same  causes 
that  created  the  original  external  furrows — want  of  cranial 
osseous  expansion).  15.  Olfactory  Sulcus  (produced  by  the 
olfactory  lobe,  which  in  man  has  dwindled  to  a  mere  tract ). 
1 8.  Orbital  Sulcus  (which  lies  directly  over  the  orbit  and  is 
created  by  lateral  and  frontal  pressure). 

Convolutoins  and  Gyri. — XV.  Lateral  Occipito-Temporal 
Convolution.  XVI.  Orbital  Convolution,  m.  Gyrus  Rectus 
(inwards  from  and  along  olfactory  sulcus).  n.  Middle  Orbital 
Gyrus.  o.  Lateral  Orbital  Gyrus. 

In  addition  to  such  fissures  and  sulci  as  are  of  constant 
appearance,  a  great  number  of  sulculi  or  lesser  furrows  of  an 
inconstant  nature  are  also  present ;  these  of  course  cannot  be 
enumerated.  In  young  children  and  imbeciles  the  sulcus  of 
Rolando  will  be  found  much  farther  toward  the  front  than  in 
fully  developed  brains.  This  is  because  the  frontal  lobe  has 


192  CLEVENGER — Physiology  and  Psychology. 

suffered  arrest  of  growth.  This  sulcus  appears  very  close  to 
the  front  in  idiots,  and  their  retreating  foreheads  are  cranial 
adaptions  to  this  defect. 

The  position  of  the  cerebellum  and  its  recognizable  phylo- 
genetic  changes  may  be  easily  traced  through  the  vertebrata 
generally,  but  the  lobes  superior  to  it  undergo  a  variety  of 
distortions  and  changes  of  position,  for  the  solution  of  which 
we  must  resort  to  schematic  views. 

Given,  a  series  of  tubercles  which  shall  from  behind  forward 
represent  the  lobes  of  the  brain,  as  follows : 

1.  Posterior  pair  of  tubercula  quadrigemina. 

2.  Anterior  pair  of  tubercula  quadrigemina. 

3.  Epiphisis  cerebri. 

4.  Mammillary  eminence. 

5.  Olfactory  lobe. 

6.  Cerebrum. 

654321 

O     O     O     O     O     O 


O       O      Q      O      Q      Q 

~ 


The  gray  secondary  of  each  being  united  by  commissures, 
the  afferent  and  efferent.  The  first  of  these  commissures  it 
will  be  most  convenient  to  follow  through  the  developmental 
gyrations  as  apparently  connecting  the  under  surface  of  each 
lobe,  but  in  reality  connecting  the  secondary  segments  per- 
taining to  each,  as  optic  thalamus,  tuber  cinereum,  olfactory 
ganglion  and  corpus  striatum. 

I  is  connected  to  2  and  3  by  the  upper  end  of  the  brachium 
conjunctivum,  3  to  4  by  prolonged  habenulae,  4  to  5  by  fornix, 
5  to  6  by  hippocampal  fibers,  tractus  Lancisi  and  gyrus  forni- 
catus  (the  latter  principally).  In  the  case  of  a  fish  with  optic 
lobe  (2)  developed  covering  the  other  tubercles,  the  course  of 


CLEVENGER — Physiology  and  Psychology.  193 

the  commissures  and  relative  mass  appearance  would  be  thus : 


3        1 


Bird,  as  pigeon,  with  cerebrum  developed  covering  I  to  5, 
the  optic  lobe  being  pressed  to  one  side. 


The  following  appears  to  be  arrangement  of  the  brain  of  the 
fox  shark,  with  lobes  equally  developed.  I  think  the  main 
mass  must  be  the  optic  thalamus,  with  the  quadrigeminal 
bodies  fused  on  its  surface  (this  latter  feature  not  represented 
here). 


5 

O 


o  o  Q 


4      3 


Ths  form  appears  in  mammal  with  large  olfactory  lobe  and 
cerebrum. 


J2PP 

5  6  4321 

This  condition  is  presented  by  an  unconvoluted,  brain  such 
as  the  beaver's,  which  is  but  faintly  fissured. 


194 


CLEVENGER — Physiology  and  Psychology. 


An  illustration  of  the  gradual  appearance  of  the   Sylvian 
fissure  with  the  hippocampal  formation,  is  attempted  below : 


The  last  cut  represents  the  Sylvian  fissure  formed  as  in  man, 
with  the  accompanying  fasicular  distortions : 


The  growth  of  the  frontal  lobe  in  proportion  to  the  intelli- 
gence of  the  primate  individual  augments  this  creation  of  tem- 
poral. Many  of  the  longitudinal  sulci  of  the  quadrumana  fold 
over  and  under  with  this  advancement  of  the  occipital  into 
temporal,  and  the  parieto-occipital  fissure  on  the  median  face 
of  the  cerebral  hemisphere  is  doubtless  created  directly  by  this 
bend,  and  the  calcarine  may  also  owe  its  origin  to  this  change. 
A  variety  of  causes  combine,  however,  in  fissure  formation, 
aside  from  those  mentioned. 

Kolliker,  Key,  Retzius,  Schwalbe,  and  other  histologists 
concur  in  the  intimate  structure  of  the  intervertebral  (some- 
times called  cerebro-spinal)  ganglia  exhibiting  medullated  sen- 
sory nerves  passing  through  without  anatomical  connection, 
and  that  some  non-medullated  fibrils  occur.  Fibrils  pass 


CLEVENGER — Physiology  and  Psychology.  195 

through  the  ganglia  and  end  in  them.  The  Ranvier  "T"  cells 
seem  to  me  to  be  comparable  to  the  Purkinje  cells  of  the  cere- 
bellum, and  as  every  interposition  of  sensory  masses  or  cells 
such  as  these  must  delay  or  destroy  impressions,  why  can  we 
not  consider  the  intervertebral  ganglia  and  Ranvier  and  Pur- 
kinje cells  as  organs  for  inhibition  ?  We  know  that  such  organs 
exist  and  that  it  is  just  as  important  that  blunting  of  impres- 
sions should  occur  as  that  others  should  be  keenly  felt. 

It  cannot  be  denied  that  a  fibril  connecting  with  a  ganglion 
cell  isolated  from  other  connections  can  have  no  associated 
relationship  with  the  cell  community  which  go  to  make  up  the 
organism. 

Let  us  assume  the  monopolar  nerve  cells  as  serving  shunt 
or  inhibitory  purposes;  and  the  consistency  of  the  supposition 
will  appear  further  along. 

Let  it  be  understood  that  it  is  not  necessary  to  regard  the 
cerebrum,  cerebellar  laminae  and  tubercles  of  the  encephalon, 
aside  from  the  Gasserian  ganglia,  as  precisely  intervertebral, 
derived  from  a  primitive  spinal  set  of  segments.  Huxley  dis- 
poses of  the  cranial  bones  derivation  controversy  by  showing 
that  the  skull  and  the  vertebrae  arose  at  the  same  time,  and 
hence  while  there  might  have  been  a  cartilaginous  tendency 
toward  segmentation,  there  was  no  necessity  for  the  previous 
vertebrae  formation  of  the  head  bones  in  full.  Precisely  thus 
the  intervertebral  tendency  was  converted  into  the  formation 
of  cerebral  lobes,  and  modifications  proceeded  rapidly  in  them. 

Gray  matter  forms  exteriorly,  because  the  interior  is  filled 
with  fibril  plexuses  which  cohere  in  fascicular  relations  with 
strands  passing  through.  Gradually  the  cortex  is  encroached 
upon  with  fibrils  and  inhibition  cells. 

The  arcuate  fibrils  pass  into  relation  with  the  corona  radiata 


196  CLEVENGER — Physiology  and  Psychology. 

as  fast  as  reason  passes  to   instinct,  doubt  to  determination, 
hesitancy  to  reflex  action,  through  training,  learning,  etc. 

Let  the  figure  below  represent  independently  acting  olfac- 
tory and  optic  ganglia,  with  fibrils  passing  through  and  ending 
in  them,  and  containing  inhibition  cells : 


Next,  by  contiguity  and  the  law  of  simultaneous  associated 
action,  as  when  a  sight  and  smell  occurred  at  once,  uniting 
fasciculi  would  be  built  up  from  the  plexiform  and  the  asso- 
ciation of  the  compound  impression  would  occur  thus : 


Thus,  arcuate  fibrils  unite  in  the  various  regions  different 
senses,  or  nerve  inhibitory  cells  finding  an  outlet  are  connected 
with  distant  areas. 

The  occipital  lobe  contains  the  cuneus  gyrus  in  which  the 
optic  filaments  abut. 

As  this  association  occurs  step  by  step,  changes  proceed.  A 
ganglion,  originally  inter  vertebral,  such  as  one  of  the  anterior 
tubercula  quadrigemina,  may,  by  association,  hand  over  its 
functions  to  the  cuneus  region  of  the  cerebrum.  Cells  in  this 
forming  optic  associations  with  others  more  anteriorly  or  else- 
where, account  for  the  heretofore  perplexing  mixture  of  abso- 
lute and  relative  brain  function  areas. 

I  do  not  think  I  can  make  this  clear  to  those  unfamiliar  with 


CLEVENGER — Physiology  and  Psychology.  197 

what  has  been  done  lately  in  cerebral  physiological  and  patho- 
logical research.  In  a  rough  way,  it  may  be  stated  that  mainly 
through  Exner's  investigations,  what  he  calls  absolute  centers 
for  the  symbolic  field  cluster  in  the  region  of  the  sulcus  of 
Rolando,  an  auditory  center  is  at  the  end  of  the  Sylvian  fissure, 
an  optic  in  the  cuneus,  etc.  But  relative  centers  or  scattered 
places  in  the  brain  occur,  where  injuries  sometimes  induce 
troubles  referable  to  other  faculties  than  those  of  the  absolute 
centers  upon  which  these  relative  centers  rest 

Follow  an  optic  thread  from  the  optic  nerve  to  the  optic 
lobe,  thence  to  the  cuneus,  thence  by  an  association  with  a 
cell  further  forward.  While  the  main  bundles  may  end  in  the 
cuneus,  the  encroachment  by  association  upon  another  center 
may  be  such  as  to  make  a  relative  center  in  another  part  of 
the  brain,  according  to  the  habits,  learning,  occupation,  ideas, 
etc.,  of  the  owner  of  the  brain. 

By  simultaneous  excitation  of  two  sense  centers  in  these 
lobes,  sight  and  audition,  or  audition  and  deglutitory  tactile, 
cohered.  Thence  over  radiating  fibrils  to  the  medulla  or  cord 
for  motor  reflex  effect. 

All  cerebral  nerves  may  be  regarded  as  sensory.  As  soon 
as  an  etape  cell  was  overcome  it  became  "  motor "  and  en- 
larged. From  this  association  of  absolute  centers  sprung  up 
a  dependency  of  the  areas,  one  upon  the  other,  so  that  where 
formerly  the  districts  were  separate,  by  development  fusion, 
etc.,  distinctions  were  broken  down  and  the  direct  conveyance 
to  a  relative  center  resulted,  though  the  absolute  area  largely 
remains,  due  to  the  recurrence  of  olden  impressions.  To  fa- 
cilitate transfer,  the  tactile,  auditory,  optic,  etc.,  centers  are  dif- 
fused and  lie  in  adjoining  layers,  with  probably  no  particular 
function  to  each  layer,  except  such  as  would  occur  through 
adaptability  of  inhibition  cell  sizes. 


198  CLEVENGER — Physiology  and  Psychology. 

The  hippocampus  major  could  have  been  built  up  through 
deglutitory  and  olfactory  senses  cohering.  It  is  well  known 
how  important  the  smelling  sense  is  in  many  of  the  lower  ani- 
mals. 

In  the  simiadae,  as  the  optic  sense  arose  in  importance  and 
largely  took  the  place  in  intelligence  of  the  olfactory,  the  cu- 
neus  fibrils  could  have  and  probably  did  in  their  definition  give 
weight  to  the  hippocampus  minor  for  deglutitory  association. 
Such  large  strands  might  appropriately  be  considered  as  having 
as  extremely  important  functions  as  these  assigned  them,  and 
yet  their  ablation  need  not  point  to  their  functions. 

The  ages  during  which  the  major  fibrils  have  been  in  use,  and 
the  comparatively  recent  formation  of  the  minor,  account  for  the 
relative  sizes,  and  the  obsolescing  features  of  the  major  may 
be  advantageously  compared  with  the  good  definition  of  the 
minor. 

Goltz*  concludes,  from  experiments  on  dogs : 

1.  That  the  cerebral  cortex  is  the  organ  of  the  mind  ;  that 
the  removal  of  large  pieces  of  each  half  of  the  cortex  dimin- 
ishes intelligence. 

2.  That  it  is   not  possible  through  destruction  of  a  section 
of  the  cortex  to  cause  paralysis  of  the  muscle. 

3.  That  it  is  also  impossible  by  a  destructive  lesion  of  the 
cortex  to  cause  a  permanent  loss  of  activity  of  the  senses.  The 
animal   has  all  his  senses.     After  the  removal  of  large  pieces 
of  the  cortex  there  ensues  weakness  of  the  perceptive  faculties. 

When  a  tract  conveying  an  impulse  in  brain  or  cord  is  in- 
jured, there  is  an  attempt  at  vicariation  by  the  contiguous  gray 
matter;  where  this  is  also  injured,  as  in  multiple  cerebro- 
spinal  sclerosis,  the  choreic  motions  may  occur,  and  in  ataxia 
the  gray  is  long  in  conveying  impressions.  Mental  action  may 
be  similarly  involved  and  in  the  same  diseases. 

*  Foster's  Journal  of  Physiology,  vol.  iv.  Nos.  4  and  5. 


CLEVENGER — Physiology  and  Psychology.  199 

Diffusion  precedes  definition,  and  the  latter  in  some  parts  is 
established  at  the  birth  of  the  child,  but  alternately  higher  and 
higher  diffusion  and  defined  tracts  arise  as  the  infant  grows 
older.  Until  the  cerebral  diffusion  apparatus  arises  in  the 
human  being  it  cannot  think,  as  we  understand  thought.  Its 
lower  reflexes  are  defined  but  not  coordinated.  Memory  be- 
gins in  the  intellectual  sphere  of  the  child  about  the  third  or 
fourth  year,  but  it  is  so  gradually  evolved  from  birth  with 
other  lower  memories  as  not  to  be  determinable  when  first  es- 
tablished. 

It  would  require  a  separate  and  larger  volume  to  fairly  enter 
into  the  details  of  the  innervations  and  changes  wrought  in  the 
brain  in  the  evolutionary  scale.  We  can  generalize  here  suf- 
ficiently by  recalling  Spitzka's  dictum,  that  as  the  association 
fibrils  multiply,  so  does  intelligence  advance. 

The  diffusion  apparatus  constantly  tends  to  definition  and 
the  higher  sense  connections  to  usurp  the  place  of  the  lower. 
Were  it  possible  for  such  a  thing  to  be  accomplished  in  full, 
psychic  life  would  cease,  for  the  intellect  depends  upon  its  ad- 
vance. Change  must  occur,  and  no  sooner  dp  higher  diffusion 
associations  result  in  defined  automatic  reflexes,  than  a  supe- 
rior condition  of  things,  or  retrogradation,  or  at  least  a  different 
state  of  things  must  ensue.  The  higher  the  animal  or  man, 
intellectually,  the  more  the  cortex  gray  is  encroached  upon  by 
fibrils;  but  were  this  process  to  be  accomplished  to  full  con- 
version into  fibrils,  the  animal  or  man  would  become  a  mere 
intellectually  lifeless  machine.  While  life  tends  toward  com- 
plete automatism,  the  safety  of  the  mind  lies  in  the  vicissitudes 
which  prevent  it. 

Another  fact  which  bears  upon  my  nerve-cell  theory  is,  that 
the  processes  of  nerve  cells  increase  in  number  in  an  ascend- 
ing scale  of  life.  As  the  inhibited  sensations  for  which  the 


2OO  CLEVENGER — Physiology  and  Psychology. 

organism  finds  no  use  cohere  with  other  impressions  and  cause 
reflection,  wonder,  or  a  search  for  an  outlet  for  the  diverted 
impressions  ensue.  The  nerve  cell  processes  would  multiply, 
and  impressions  eventuate  in  movements  which  the  animal, 
either  mistakenly  or  correctly,  considers  serves  some  useful 
purpose. 

Volitional  impulses,  according  to  Vulpian,*  are  confined  to 
the  lateral  columns  in  the  cervical  regions,  though  in  dorsal 
and  lumbar  regions  in  anterior  columns  as  well. 

Schiff  distinguishes  between  tactile  and  general  sensibility, 
and  locates  them  in  gray  and  white  parts  of  the  cord.  Phys- 
iologies, such  as  Foster's,  detail  these  matters  satisfactorily, 
and  reference  should  be  made  to  such  works  for  what  cannot 
be  embraced  here. 

As  the  fibrils  are  best  furnished  in  the  region  of  the  cord, 
and  the  plexus  fibrils  being  drawn  upon  to  form  the  segmental 
nerves  first,  the  longitudinal  fibrils  will  cling  to  and  form  from 
the  gray  cord  and  follow  its  length.  The  shock  of  a  nerve 
impulse  is  not  thus  sent  direct  from  the  brain  to  the  muscular 
segments,  but  to  the  levels  of  the  cord  and  thence  to  the  mus- 
cles over  their  motor  nerves.  Hence,  all  motor  influences  or- 
iginate in  the  gray,  otherwise  tetanic  spasms,  epilepsies,  would 
occur  as  a  rule  instead  of  exceptionally.  The  sensory  longitud- 
inal columns  arose  by  the  same  laws  of  definition.  With  the 
more  intense  and  frequent  impulses,  in  head  to  tail  directions, 
the  plexus  fibrils  arrange  themselves  longitudinally  in  lines 
of  least  resistance. 

By  adjustment  it  seems  that  a  nerve  arranges  its  molecules 
so  as  to  require  a  stimulus  above  a  certain  rate,  and  below  an- 
other to  react.  Different  nerves  are  placed  within  reach  of 
certain  stimuli  mainly  by  conjoined  apparatus  and  placed  be- 

*  Syst.  Nerv.,  lee.  xvii. 


CLEVENGER — Physiology  and  Psychology.  20 1 

yond  the  reach  of  other  stimuli,  so  that  general  impressions 
are  disregarded  in  favor  of  special  impressions.  The  internal 
central  connections  then  only  operate  when  the  stimulus  to 
which  they  are  adjusted  is  reached. 

The  development  of  the  symbolic  field  in  the  brain  is  what 
raised  the  forehead  angle,  and  also  enabled  man  to  cope  bet- 
ter with  his  enemies  and  survive. 


202  CLEVENGER — Physiology  and  Psychology. 


CHAPTER    XII. 
PRIMARY  ACTIVITIES. 

Sensation.  Approximate  definitions  only  are  possible  in  a 
world  where  everything  is  relative.  Metaphysicians  waste 
much  time  in  seeking  the  absolute  in  everything.  Physiolo- 
gists and  the  fairly  educated  are  satisfied  with  approximations, 
and  the  rest  of  mankind  must  be  content  with  the  knowledge 
that  a  perfect  definition  never  existed. 

Sensations  are  conditions  of  the  molecules  realized  in  con- 
sciousness, and  as  consciousness  is  necessary  to  sensation,  the 
former  is  evoked  by  the  latter,  and  physiologically  may  be 
considered  identical  with  it.  Charles  Darwin  confessed  his  in- 
ability to  understand  what  writers  generally  meant  by  con- 
sciousness. Many,  like  Brown-Sequard,  were  perpetually  en- 
tangling their  readers  with  the  two  terms  used  synonymously 
and  separately.  Schiff,  and  others  prefer  the  words  general 
sensibility  in  place  of  consciousness.  This  serves  generically 
to  inchide  special  sensation. 

Condillac  properly  derived  all  mental  processes  from  sensa- 
tion. James  Mill  reduces  the  phenomena  of  mind  to  sensa- 
tion, ideas,  and  the  association  of  ideas :  "  In  the  physical 
world  there  is  only  one  fact,  sensation,  only  one  law,  associa- 
tion," he  wrote. 

Consciousness  is  also  used  in  the  sense  of  cognition. 

The  relative  conditions  of  the  organism  begin  in  the  relative 
activities  of  the  cell  molecule,  wherein  motion  and  sensation 
are  identical.  The  end  of  sensation  or  conscious  feeling  being 


CLEVENGER — Physiology  and  Psychology.  203 

to  produce  molar  motions,  which  render  further  consciousness 
possible  and  conserve  the  life  of  the  organism,  step  by  step  the 
activities  develop  from  indefinite  to  definite,  from  indeterminate 
illy  coordinated  motions  to  determinate  coordinate  motions. 
From  those  illy  fitted  to  cope  with  the  environment  to  those 
which  through  more  sensual  reflexes  to  higher  emotional  ex- 
pression and  finally  intellectually  directed  motions  enable  the 
animal  to  admirably  adjust  itself  to  the  environment. 

Sensation  and  memory  are  at  the  base  of  all  mental  activity. 
The  molecular  organic  motions  and  through  adjustability  the 
repetition  of  those  motions  forming  the  lowest  stage  of  conscious 
feeling,  the  beginning  of  which  we  can  never  remember,  but 
which  has  evolved  from  the  molecular  activities  and  relapses 
into  unconsciousness  as  fast  as  perfect  adjustment  to  the  environ- 
ment is  made. 

The  law  of  relativity  and  the  fact  that  consciousness  is  pro- 
portioned to  change,  and  fades  with  invariability  of  impres- 
sion, are  thus  connected.  The  constant  readjustment  is  the 
condition  of  consciousness  and  life. 

Consciousness  gradually  evolves  into  what  we  call  mind, 
which  has  sensation  and  memory  at  its  foundation,  and  mind 
is  divisible  into  Feelings  and  Cognitions  with  their  revivabili- 
ties  or  memories. 

The  primitive  molecular  dissonances  orpainful  states  consti- 
tuting feeling,  desire,  or  sensation,  were  Hunger  and  Locomo- 
tory  desire,  the  latter  being  consequent  upon  the  first.  As 
consequences  of  both  of  these  came  the  desire  to  Excrete  and 
Sexual  desire,  both  being  in  the  amoeba  identical  and  inti- 
mately associated  with  the  Hunger  desire.  These  primitive 
desires  were  painful  in  proportion  to  their  being  ungratified, 
and  pleasurable  relatively  if  previous  gratifications  were  denied 
them.  All  of  these  desires  would  cease  to  be  conscious  states 


2O4  CLEVENGER — Physiology  and  Psychology. 

when  privation  and  satisfaction  were  so  balanced  as  to  make 
supply  and  demand  equal.  In  all  stages  of  life  we  find  this 
true.  An  easily  obtained  living  ceases  to  afford  pleasure. 
Degradation  ensues  upon  absence  of  necessity  for  exertion. 
Parasitism  in  animals,  as  in  men,  extinguishes  higher  differen- 
tiated abilities,  and  as  with  the  "nobility"  of  monarchical  gov- 
ernments, degeneracy  is  inevitable  upon  constant  receipt  of 
quid  without  rendering  the  quo. 

Upon  these  primitive  desires,  sensations  or  feelings  (it  is  of 
no  consequence  what  they  may  be  called)  may  be  erected  all 
the  subsequently  acquired  molecular  activities  evinced  in  mo- 
lar activities. 

Taking  consciousness  as  in  one  of  its  primitive  stages  (we 
cannot  say  its  lowest,  for  we  know  nothing  as  to  beginnings) 
represented  by  the  atomic  and  grosser  motions  of  the  amoeba, 
co-extensive  with  sensation  such  as  the  amoeba  may  possess,  step 
by  step  with  the  correlations  of  the  cells,  we  reach  the  highest 
consciousness  known  to  us,  that  of  man.  The  consciousness 
of  the  lowest  man  is  like  that  of  low  animals  in  general,  and 
that  of  highly  differentiated  animals,  such  as  the  chimpanzee, 
approximates  that  of  the  average  man  who,  through  circum- 
stances and  want  of  training,  bothers  his  brains  about  little 
else  than  immediate  creature  comfort.  From  what  has  been 
considered  mere  automatism  to  the  consciousness  of  impressions, 
such  as  the  prick  of  a  pin, thence  to  "consciousness  of  the  ego," 
Schiff  *  has  demonstrated  degrees  marked  by  heat  evolution, 
and  Prof.  Herzen  f  shows  that  central  acts  accompanied  most 
vividly  by  consciousness  are  those  which  require  a  more  ex- 
tended decomposition  and  cause  greater  calorification,  and  that 
consequently  the  intensity  of  consciousness  is  in  direct  ratio 


*  Archives  de  Physiologic,  1869,  Nos.  I  and  2. 
f  Journal  of  Mental  Science,  London,  April,  1884. 


CLEVENGER — Physiology  and  Psychology.  205 

to  the  intensity  of  the  functional  disintegration,  and  inverse 
ratio  to  the  facility  and  rapidity  of  central  transmission. 

The  metaphysicians'  quandary  over  the  ego  consciousness 
comes  from  their  not  duly  considering  the  fact  that  each  of  us 
is  only  conscious  of  himself  objectively.  We  are  conscious 
even  of  our  clothing,  as  is  very  evident  to  others,  according  to 
its  character.  You  know  yourself  objectively  by  the  impres- 
sions your  objective  self  make  upon  your  subjective  conscious- 
ness, and  as  Maudsley  says,  such  considerations  have  nothing 
to  do  with  man  in  general,  for  no  one  but  the  educated  white 
man,  as  a  rule,  would  cogitate  over  such  a  matter.  Man  feels, 
he  knows  not  why,  and  seldom  does  he  care  or  seek  to  know 
why.  All  his  impressions  have  an  objective  origin.  Even  his 
thought  is  an  effect  of  a  chain  of  antecedent  extrinsic  causes. 

We  cannot  deny  consciousness  to  every  atom  of  the  universe. 
We  have  reason  to  assign  it  to  organic  matter,  especially  living 
protoplasm,  as  that  composition  of  molecules  which  culminates 
in  the  gray  matter  of  the  nerve  centers. 

Hence,  so  far  as  animals  are  concerned,  consciousness  in 
different  degrees  resides  in  every  cell  of  their  bodies,  but  more 
especially  in  the  neurogliar  nerve  centers. 

Memory  is  simply  a  repetition  of  a  sensation.  Through  re- 
currences of  impressions  the  molecular  adjustment  of  the  or- 
ganism results.  Each  recurrence  is  consciously  or  unconsci- 
ously remembered  as  similar  to  the  original  impression.  As- 
sociated molecular  disturbances,  no  matter  how  induced, 
whether  by  conditions  of  the  blood  or  vibrations  approxi- 
mating those  of  the  impression,  suffice  to  recall  or  reproduce 
it.  For  example,  a  sensation  may  be  likened  to  a  note  pro- 
duced on  a  violin-string  by  the  bow  being  drawn  across  it.  If 
the  note  be  reproduced  by  any  other  means,  such  as  vibration 
in  harmony  with  another  instrument,  such  reproduction  may 


206  CLEVENGER — Physiology  and  Psychology. 

be  likened  to  memory.  In  the  insane,  these  revived  sensations, 
through  absence  of  ability  to  make  mental  correction,  are  often 
mistaken  for  the  real  ones,  and  are  the  bases  of  hallucinations 
and  delusions. 

When  one  forgets,  for  the  time  being,  something  he  wished 
to  have  remembered,  the  excitement  of  other  recollections  or 
brain  activities  interfere  with  the  process.  The  vaso  motor 
supply  in  certain  regions  relatively  obliterates  the  activity  of 
other  regions.  Memory  flags  when  the  circulation  is  bad  or 
low,  showing  how  the  blood  is  important  in  the  revivification 
of  adjustment  appreciation.  The  instability  of  the  molecules 
of  the  amoeba  would  confine  its  memory  possibilities  to  food 
relations. 

When  portions  of  the  brain  are  destroyed,  other  mental 
activities  may  adopt  new  channels,  but  memory,  depending 
upon  the  integrity  of  the  part  usually  impressed,  cannot,  when 
destroyed,  as  a  rule,  be  reinstated  in  such  ways. 

Excitement  consists  of  every  degree  of  activity,  from  the 
molecular  movements,  which  constitute  sensation  of  all  grades 
and  intensities  through  all  bodily  activities,  to  the  violence 
of  maniacal  furor.  It  is  manifested  in  all  sensory  and  motor 
events,  but  is  customarily  classed  among  emotional  states, 
though  it  would  be  an  error  not  to  recognize  it  in  other  ac- 
tivities, mental  especially. 

Excitement  may  be  pleasurable,  painful,  or  unconscious.  It 
may  also  be  definite,  or  indefinite,  depending  upon  circum- 
stances, and  whether  established  or  diffuse  outlets  for  its  ex- 
pression are  found. 

Pain  and  Pleasure  are  fundamental  conditions  of  dissonance 
and  consonance,  and  cannot  be  confined  to  emotional  states 
alone.  The  law  of  relativity  is  operative  in  creating  degrees 
of  pain  and  pleasure,  and  often  changing  one  into  the  other. 


CLEVENGER — Physiology  and  Psychology.  207 

Sleep  and  its  Phenomena. — It  is  well  demonstrated  that  in 
sleep  the  brain  is  comparatively  anaemic,  and  there  is  during 
sleep  a  necessity  for  maintaining  a  minimum  of  blood  there. 
The  circulation  is  slowed  and  equalized  throughout  the  body ; 
an  evenness  of  reparative  processes  proceeds.  During  activity 
the  different  parts  of  the  organism  have  been  unequally  excited 
and  an  excess  of  waste  over  the  instant  repair  has  accumulated 
to  make  further  activity  disagreeable,  if  not  painful  or  impos- 
sible. 

In  the  amoeba  the  quiescent  plethoric  state  facilitates  full 
assimilation.  Imagine  one  cell  of  the  morula  form  badly  nour- 
ished through  over  exercise,  and  another  cell  congested,  the 
remainder  in  variable  states  of  nutrition  and  activity.  The 
equilibrium  of  the  cells  can  be  restored  by  ceasing,  as  far  as 
possible,  activities  of  the  organism  which  tend  to  hypernutri- 
tion  of  one  cell  and  diminished  supply  to  another.  The  pabu- 
lum diffuses  itself.  Where  one  cell,  through  great  hunger,  kept 
up  an  active  demand  upon  the  others,  sleep  or  quiescence  of 
all  would  be  disturbed  until  the  activity  diminished.  It  is  for 
this  reason  that  sleep  does  not  always  appear  when  needed. 
The  laborer  whose  brain  has  not  been  particularly  hyperaemic 
but  whose  muscles  are  tired — exhausted  through  their  cell  waste, 
with  withdrawal  of  most  sense  stimuli,  as  light,  sound,  etc., 
"  drops  off  quickly  to  sleep."  Not  so  the  student  whose  brain 
is  engorged  with  blood.  In  spite  of  stimuli  withdrawal,  wake- 
fulness  persists.  Active  or  passive  hyperaemia  takes  a  longer 
time  for  bodily  equilibration.  Frictions,  baths,  etc.,  assist  this 
by  diffusing  the  blood  supply,  and  probably  a  nocturnal  meal 
would  facilitate  release  from  congestion  of  the  head  by  "drain- 
ing "blood  to  the  stomach ;  but  excessive  digestive  function 
going  on  is  not  rest,  and  it  is  only  by  practice  that  this  is  tol- 
•erated  or  adjusted  to. 


2o8  CLEVENGER — Physiology  and  Psychology. 

A  not  very  hearty  meal  at  night  might  assist  the  student. 

The  growing  child  needs  more  sleep  than  the  adult,  for  the 
reason  that  the  growth  processes  demand  long  intervals  of 
freedom  from  activities  directed  in  other  than  growth  channels. 

The  aged  need  less  sleep,  for  involution  renders  attempts  at 
reparation  largely  abortive.  The  cells  are  growing  less  capa- 
ble of  activity,  they  need  less  repair  and  could  not  assimilate 
so  freely  as  when  young,  and  there  is  a  quantitative  lessening 
of  the  cell  number  also.  The  faculties  grow  more  obtuse  and 
are  not  using  up  material,  hence  what  little  reparative  need 
there  is,  a  few  hours  furnishes. 

Animals  differ  as  to  their  needs.  Some  sleep  by  "  snatches," 
others  hibernate,  when,  during  a  season  of  dearth,  food  is  not 
easily  obtained ;  as  sleep  minimizes  the  tissue  loss  it  is  resort- 
ed to.  Other  animals  and  men,  through  stress  of  circum- 
stances, as  when  living  in  polar  regions,  grow  to  disregard  the 
presence  of  light  during  sleep,  by  a  process  similar  to  that 
which  enables  one  to  sleep  with  a  lamp  alight  in  the  room. 
Nocturnal  animals  also,  who  have  adapted  themselves  to 
prowling,  acquire  the  ability.  Napoleon  is  said  to  have  pos- 
sessed the  power  of  dropping  off  to  sleep  in  spite  of  activity 
in  the  neighborhood. 

Unpleasant  excess  of  heat  stimulates  to  awakening,  and  one 
so  over  stimulated  will  fall  off  to  sleep  immediately  on  being 
cooled  off. 

Huebel*  describes  forced  hypnotism  in  cold  blood  verte- 
brates by  holding  a  frog,  without  paining  it,  excluding  light, 
sounds  or  any  other  nerve  stimuli ;  the  animal  sleeps  for  hours 
even  in  a  constrained  position.  This  indicates  what  can  be 
deduced  from  other  matters,  that  sleep  is  a  withdrawal  of  vi- 
bratory sense  stimulation,  to  which  the  higher  centers  re- 

*Pfluger's  Archiv. 


CLEVENGER — Physiology  and  Psychology.  209 

spond,  and  as  the  spinal  cord  sleeps  by  resting  the  muscles,  so 
do  the  optic,  auditory,  etc.  centers  by  resting  peripheral  organs. 

The  heart  muscle  is  compelled  to  rest  in  the  interim  of 
beats,  and  it  is  calculated  that  it  receives  eight  of  the  twenty- 
four  hours  for  this  purpose.  Then  with  the  lessened  heart 
action  during  sleep,  repair  to  the  organ  is  further  favored. 

The  stimuli  withdrawal  from,  cerebro-spinal  nerves  instantly 
(if  other  things  are  equal )  stays  the  nutrient  reflexes.  No 
more  blood  in  excess  is  sent  to  the  head,  the  fall  of  blood 
pressure  in  the  medulla  drops  the  heart  beats  to  a  lesser  num- 
ber through  pneumogastric  action,  and  the  equalizing  pressure 
begins.  Where  an  impression,  emotion  or  other  brain  activity 
is  too  great  to  allow  its  blood  to  depart  from  the  region  of  the 
brain  involved,  then  diverting  the  mind  by  calling  to  it  a  dif- 
ferent train  of  thought,  through  a  chain  of  antecedent  causes, 
may,  and  sometimes,  not  always,  does  act  derivatively  to  dis- 
tribute the  blood  and  permit  sleep. 

Normal  sleep  should  be  dreamless,  but  when  dreams  occur 
it  is»  through  some  cell  activity  about  the  body  which  has  been 
aroused  and  suggested  feebly  or  strongly  through  the  particular 
area  of  the  brain  to  which  the  blood  is  sent  or  drawn.  The 
fibrils  and  sensory  cells,  thus  thrown  into  erratic  activity,  re- 
vive the  vibrations  to  which  they  were  subjected  in  the  past, 
and  as  these  blood  interferences  with  sleep  approach  more  the 
methods  normally  obtaining  during  waking  hours,  so  will  the 
vividness  and  consecutiveness  of  the  dream  or  nightmare  from 
congestion  be.  Where  first  one  part  and  then  another  part 
of  the  brain  is  thus  supplied  with  blood,  through  internal  or 
external  stimulation,  the  most  absurd  association  systems  are 
temporarily  formed,  and  with  pathological  conditions  to  favor 
this,  through  extinction  of  the  ability  to  correct  such  impres- 
sions through  other  senses,  or  by  reason  in  waking  states,  in- 

14 


2io  CLEVENGER — Physiology  and  Psychology. 

sanity,  with  delusions,  hallucinations  and  illusions,  is  induced. 
False  association  is  at  the  root  of  many  formes  of  insanity, 
if  not  all  forms. 

"Two  of  Vierordt's  pupils,  Monninghoff  and  Piesbergen, 
have  made  the  depth  of  sleep  the  subject  of  investigation.  The 
depth  of  sleep  is  proportional  to  the  strength  of  the  sensory 
stimulus  necessary  to  awaken  the  sleeper,  that  is,  to  call  forth 
some  decisive  sign  of  awakened  consciousness.  As  a  sensory 
stimulus  they  made  use  of  the  auditory  sensation  produced  by 
dropping  a  lead  ball  from  a  given  height.  The  strength  of  the 
stimulus  was  reckoned,  in  accordance  with  some  recent  inves- 
tigations of  Vierordt,  as  increasing,  not  directly  as  the  height, 
but  as  the  0.59  power  of  the  height.  For  a  perfectly  healthy 
man,  the  curve  which  they  give  shows  that  for  the  first  hour 
the  slumber  is  very  light;  after  I  hour  and  15  minutes,  the 
depth  of  sleep  increases  rapidly,  and  reaches  its  maximum 
point  at  i  hour  and  45  minutes ;  the  curve  then  falls  quickly 
to  about  2  hours  1 5  minutes,  and  afterwards  more  gradually. 
At  about  4  hours  30  minutes,  there  is  a  second  small  rise 
which  reaches  its  maximum  at  5  hours  30  minutes,  after  which 
the  curve  again  gradually  approaches  the  base  line  until*  the 
time  of  awakening.  Experiments  made  upon  persons  not  per- 
fectly healthy,  or  after  having  made  some  exertion,  gave  curves 
of  a  different  form."* 

The  withdrawal  of  stimuli  voluntarily,  through  closing  the 
eyes,  is  only  partial ;  noises  are  heard,  and  the  blood  does  not 
immediately  fall  to  a  minimum  in  the  brain ;  hence,  in  most 
cases,  sleep  cannot  appear  until  time  has  passed.  As  the  nu- 
trient, sympathetic,  or  vaso  motor  reflexes  are  less  and  less 
called  upon,  an  ebb  of  blood  from  the  brain  finally  admits  of 
obtuseness  to  noises,  etc.,  when  they  do  occur.  With  the  res- 
toration of  general  cell-nutrition  the  desire  for  activity  in- 
creases, and  the  reflexes  are  easily  provoked.  The  nutrient 

*  Zeitsch.  f.  biol.,  xix.  114. 


CLEVENGER — Physiology  and  Psychology.  2 1 1 

reflexes  of  the  brain  now  begin  to  send  blood  there  upon 
stimulation,  and  the  man  awakes  with  the  increased  noises 
and  light  of  day,  or  upon  slighter  provocation,  if  these  are  ab- 
sent. 

The  condition  of  the  health  and  many  other  matters  vary 
the  phenomena,  but,  as  a  rule,  the  foregoing  is  about  the  pro- 
cess. 


2 1 2  CLEVENGER — Physiology  and  Psychology. 


CHAPTER    XIII. 

DERIVED  ACTIVITIES,  MAINLY  THE  EMOTIONS  AND  THEIR 
EXPRESSION. 

Pain  or  pleasure  to  an  amoeba  could  only  be  judged  of  ob- 
jectively as  excitement,  increased  activity,  and  the  fundamen- 
tality  of  excitement  is  shown  in  all  animals  while  experiencing 
either  or  both  feelings.  All  emotional  activity  is  excitement, 
even  if  not  expressed  in  any  way.  The  suppression  of  the 
emotion  itself  is  an  excitement. 

Wundt*- affords  numerous  proofs  of  the  highly  developed 
animals  standing  nearer  to  man  than  to  lower  animals  of  their 
own  genus  even,  hence  it  is  not  proper  to  regard  the  emotions, 
etc.,  of  the  dogs  and  apes  in  any  other  way  than  with  our 
own,  not  as  leading  up  to  ours.  Many  of  the  higher  mental 
acts  of  such  animals  have  been  developed  at  the  same  time 
with  our  own,  and  for  the  same  reasons.  We  can  simplify  our 
treatment  of  the  subject  in  this  way,  and  work  closer  to  first 
principles. 

The  amoeba  is  unable  to  express  the  difference  between  that 
which  is  dissonant  among  its  molecules  and  that  which  is  con- 
sonant with  their  workings. 

Pain  or  pleasure  activity  in  synamcebaor  planeaeda  could  not 
be  judged  apart.  In  the  latter,  ciliary  motions  would  be  in- 
duced by  either,  but  with  the  worm,  provided  with  a  low  ner- 
vous system  badly  coordinated,  efforts  to  move  would  be  made 
by  both  feelings.  The  pleasurable  feeling  would  be  referred 

*  Vorlesungen  iiber  die  Menschen  und  Thierseele.     Leipzig,  1863. 


CLEVENGER — Physiology  and  Psychology.  2 1 3 

directly  to  assimilation,  but  in  the  worm,  and  probably  lower, 
pain  could  not  be  referred  to  and  induce  the  excretory  locomo- 
tory  motions.  As  the  expulsion  of  CO2  and  other  inert  mat- 
ter from  the  body  is  associated  with  unpleasant  feelings,  inter- 
ferences, so  all  pain  has  reference  to  this,  and  thus  in  all  ani- 
mal life  involuntary  evacuations  may  be  induced  if  the  dis- 
agreeable sensation  may  not  be  disposed  of  upon  determinate 
motor  channels  in  other  ways.  This  fundamental  pleasure 
and  pain  excitement,  ingestion  and  retarded  evacution,  may 
exchange  places  in  retarding  the  assimilatory  and  facilitating 
the  excretory  if  previously  opposite  conditions  existed. 

Relativity,  as  Bain  shows,  must  be  perpetually  kept  in  view 
in  discussing  the  emotions,  but  the  foundation  of  painful  emo- 
tions is  in  assimilation  interference,  of  which  excretion  is  an 
associated  act,  and  pleasurable  emotions  are  grounded  upon 
gratification  of  hunger,  of  which  excretion  is  a  consequence. 
The  association  in  sequence  is  so  direct  in  cell  life  that  it  has 
implanted  itself  below  all  subsequently  acquired  feelings  as  a 
basis. 

The  vulgar  expressions,  "good  enough  to  eat,"  and  mention 
of  sounds  being  "sweet,"  show  the  close  relationship  of  all 
pleasures  to  the  gustatory  sense.  Conversely,  epithets  of  dis- 
like are  full  of  references  to  expulsive  functions.  The  expres- 
sion of  disgust  is  a  faint  semblance  of  vomiting.  The  sneer 
indicates  that  the  nostrils  are  closed  against  a  bad  odor.  In 
the  lowest  forms  of  life,  then,  all  pleasure  and  pain  had  ref- 
erence to  the  ingestive  and  excretory  functions.  Where, 
through  too  great  pain,  an  interference  with  the  ingestive  mo- 
bility was  produced,  then  "  low  spirits  "  would  be  expressed, 
and  this  mode  of  expression  through  supineness  pervades  all 
the  cells  of  the  organism  when  that  condition  occurs  in  higher 
animals.  The  nutritive  functions  are  interfered  with  in  all 
during  mental,  nervous  or  other  cellular  prostration. 


214  CLEVENGER — Physiology  and  Psychology. 

Excitement  in  all  animals,  to  the  very  lowest,  whether  pain- 
ful or  pleasurable,  may  be  evinced  in  tremblings,  modified 
secretions,  perspiration  in  excess,  whenever  there  are  not  defi- 
nite means  of  conversion  of  the  diffusion  into  evolved  channels 
for  their  expression. 

With  the  better  association  of  the  cells  through  a  nervous 
system,  appropriate  motions  can  be  made,  the  offensive  sub- 
stance can  be  expelled  or  suitable  movements  made  to  swallow 
the  pleasant  substance,  the  presence  of  which  produced  the 
sensations.  When  the  muscles  are  arranged  to  facilitate  these 
acts,  associated  serviceable  habit,  the  principle  discovered  by 
Darwin,*  will  group  pain  and  pleasure  expressions  generically 
into  certain  muscular  expressions.  Thus,  all  pain,  whether 
bodily  or  mental,  produces  motions  which  were  originally  use- 
ful, such  as  contraction  of  the  brow  and  closure  of  the  eyes 
upon  receipt  of  painful  intelligence,  as  though  to  avoid  a 
Strong,  painful  light. 

An  expression  originally  serviceable  may  persist  through 
habit,  even  when  positively  unserviceable,  just  as  the  pageantry 
and  buffoonery  of  monarchical  ceremonies  persist,  though  the 
multitude,  as  the  years  advance,  are  inclined  to  look  upon  them 
with  growing  disfavor  and  contempt. 

Disgust  underlies  all  other  painful  experiences,  and  its  ex- 
pression indicates  a  desire  to  rid  the  stomach  of  an  offensive 
substance.  No  matter  what  disgusts  us,  it  has,  through 
our  muscular  expression  and  language,  this  primary  signifi- 
cance. 

The  intimate  association  of  all  forms  of  disgust  with  stomach 
and  intestinal  distress  was  fully  shown  by  a  Westerner,  when 
looking  over  his  hotel  register,  promptly  depositing  his  just 
eaten  dinner  thereon  upon  seeing  Oscar  Wilde's  name  in- 

*  Expression  of  the  Emotions  in  Man  and  Animals. 


CLEVENGER — Physiology  and  Psychology.  2 1 5 

scribed   in  the    record.     An  antipathy  to  the   dudesque  was 
coupled  in  this  case  with  an  irritable  stomach. 

Offensive  odors,  when  strong  enough  to  interfere  with  respi- 
ration through  imperfect  oxygenation,  excite  the  same  disgust, 
feelings  and  expressions. 

Such  odors  as  do  not  interfere  with  respiration  are  offensive 
or  pleasant  through  association,  as  is  well  attested  by  animals, 
savages,  and  even  civilized  men  acquiring  a  relish  for  what  to 
others  are  malodorous  edibles. 

In  the  low  forms,  from  amoeba  to  the  worm,  we  see : 

Excitement,  molecular  and  molar,  as  a  result  of  the  dis- 
sonant and  consonant  changes  which  constitute  pain  and 
pleasure,  and  faintly  set  forth  evidences  of  these  primitive  ani- 
mals experiencing 

Low  and  High  Spirits,  according  to  whether  the  feelings  are 
disagreeable,  dissonant,  or  agreeable,  consonant. 

Dejection  and  Joy  are  merely  synonyms  for  the  above. 
Despair  and  Grief  also  express  the  same  thing  as  dejection  and 
low  spirits,  only  they  are  more  intense,  and  should  be  reserved 
till  the  senses  are  more  developed  and  consciousness  is  more 
acute. 

All  these  feelings  are  expressed  to  this  low  stage  by  excite- 
ment and  hot  very  well  coordinated  movements  directed  to 
achieve  ends. 

These  diffused  impressions  occur  in  man  and  induce  the 
badly  coordinated  motions,  such  as  trembling,  etc.,  for  the 
same  reason  that  they  affect  the  protozoa  and  lower  metazoa 
in  a  similar  way,  because,  for  the  time  being,  there  is  no  out- 
let for  the  feeling,  the  impression  cannot,  through  its  over 
intensity  or  its  newness,  find  the  proper  manner  of  adapting 
motions  suitable  to  it.  In  painful  conditions  this  constitutes 
Fear,  which  can  come  only  with  the  establishment  of 'memory. 


216  CLEVENGER — Physiology  and  Psychology. 

As  soon  as  the  molecular  adjustment  to  eating  is  stable,  the 
memory  adjustment  is  aroused,  and  with  hunger  pain  and 
memory  adjustment  in  the  protozoa  came  the  development  of 
what  in  higher  animals,  with  nervous  systems,  could  be  re- 
cognized as  fear,  which,  from  its  origination,  was  associated 
with  the  excretory  desire  or  the  want  to  get  rid  of  troublesome 
interfering  substances.  In  all  animals  excess  of  fear  will  act 
upon  the  excretory  organs. 

Fear  is  gradually  evolved  as  the  amoeba  and  its  descendants 
have  frequently  experienced  pain.  The  memory  of  the  pain 
(  revivification  of  the  molecular  movements  previously  induced 
by  a  pain )  imparts  a  vague,  distressed  sensation  tending 
toward  dejection,  and  when  the  feeling  is  revived,  according 
to  the  strength  of  the  influence  in  animals  with  nervous  sys- 
tems, and  no  adjusted  arrangement  for  the  impression  in  mus- 
cular contractions  or  means  of  escape,  degrees  of  fear  arise 
beginning  with  disagreeable  feelings,  passing  through  disgust 
and  culminating  in  Terror,  which  diffuses  the  strength  and  often 
acts  upon  the  bowels  through  its  primal  association  with  ex- 
cretory impediment  feeling. 

In  all  cases  of  doubt,  fear,  distress,  etc.,  there  are  "sinkings 
at  pit  of  stomach,"  and  in  extreme  cases  visceral  disturbance 
to  the  extent  of  seminal,  fceces,  or  urine  voiding. 

Fear  of  the  unknown  is  always  the  most  terrible  ;  the  inabil- 
ity to  adjust  suitable  means  of  escape  thus  make  anticipation 
greater  than  the  reality.  "Prostration  of  the  nervous  system  " 
frequently  follows  this  sort  of  dread.  It  is  a  formidable  force 
in  nature  and  affects  all  animals.  It  is  especially  poignant  in 
savages  and  barbarians,  and  is  the  basis  of  all  their  superstitions 
They  are  ready  to  listen  to  any  one  who  has  a  theory  of  the 
unknown,  providing  no  theory  has  previously  been  accepted 
in  which  case  the  new  theorist  is  likely  to  be  immolated.  Fear 


CLEVENGER — Physiology  and  Psychology.  217 

is  the  idol  and  fetich-maker,  and  in  all  countries  whoever  can, 
through  established  custom,  successfully  maintain  himself  as  an 
interposing  power  between  the  frightened  and  the  dreaded 
unknown,  may  thrive  upon  such  claims  and  even  come  to  be- 
lieve that  he  possesses  such  intermediating  power. 

As  soon  as  acts  become  adjusted  to  ends,  and  the  animal 
knows  what  to  do  to  avoid,  escape  from,  or  to  destroy  his  enemy 
or  the  inimical  disagreeable  thing;,  as  soon  as  easy  avoidance 
of  the  hateful  impression  is  furnished  by  acts  of  the  muscles, 
which  means  that  the  nervous  system  has  found  its  proper 
associations  with  muscles,  then  the  efforts  thus  aroused  affording 
the  escape,  in  the  knowledge  that  escape  may  be  made, — even 
though  the  knowledge  may  turn  out  to  be  illusory, — the  feeling 
of  defiance,  Anger,  arises.  Fear  is  no  longer  felt,  but  with  the 
combative  motions  is  felt  a  tenseness  of  the  muscles,  through 
outflow  of  force  in  definite  directions  over  better  coordinated 
nervous  systems.  (Anticipating  here,  somewhat,  I  believe  such 
tenseness  arising  in  muscles,  as  in  the  form  of  insanity  known 
as  Katatonia,  suggests  to  the  mind  the  combative  feelings  of 
this  disorder).  Anger  supercedes  fear,  and  as  fear  excitement 
arose  because  there  was  not  an  outlet  for  it,  anger  arose  because 
the  outlet  in  effort  was  possible. 

Contempt  may  now  be  more  safely  expressed,  or  if  Rage  be 
provoked  through  intensification  of  the  anger,  the  destructive 
eating  propensities  are  exhibited  in  the  canine  tooth  exposure, 
destruction  being  associated  with  eating,  and  brawlers  threaten 
to  eat  each  other  up  every  day. 

Hatred  is  the  disagreeable  feeling,  which,  having  its  lowest 
terms  in  disgust,  has  its  highest  in  anger  and  contempt. 

Contempt  is  that  disposition  to  show  disgust  whenever  the 
anger  effort  makes  it  safe  to  do  so.  It  is  seldom  exhibited 
when  it  is  considered  to  be  unsafe.  Anger  effort  fixes  the 


2 1 8  CLEVENGER — Physiology  and  Psychology. 

muscles  in  various  ways,  according  to  the  muscular  structure 
of  the  animals.  Some  birds  and  other  forms  fluff  out  their 
feathers  or  swell  themselves  up,  all  draw  themselves  up  to  their 
full  height,  to  appear  as  formidable  as  possible.  Ears  of  horses 
are  drawn  back  out  of  the  way  of  the  antagonist's  bites.  Fear 
may  also  cause  similar  movements,  showing  the  relationship 
of  the  two.  Fear  will,  like  anger,  erect  the  hair  of  some  ani- 
mals and  man,  partly  from  diffusion  of  nerve  impulse,  and 
partly  through  serviceable  associated  habit.  Probably  diffu- 
sion caused  the  first  effect,  and  as  it  served  a  purpose  in  fright- 
ening an  antagonist,  it  has,  to  some  extent,  been  perpetuated. 
The  enraged  bull  paws  the  earth ;  this  was  originally  useful 
in  the  dirt  being  thrown  up  in  driving  off  flies. 

In  almost  all  stages  of  excitement,  diffusion  opens  the  eyes 
widely,  the  secondary  useful  object  being  to  see  better, 

Astonishment  is  thus  expressed  and  the  eyes  are  opened, 
often  the  mouth ;  the  ear  muscles  are  made  tense,  and  the  res- 
piration is  slowed,  because  a  new  impression  is  affecting  the 
diffusion  apparatus  and  a  sensation  is  trying  to  find  some  kind 
of  an  association  for  its  outlet,  and  the  diffusion  through  the 
nutrient  reflex  draws  blood  from  other  active  parts,  dropping 
their  workings  to  a  lower  grade  of  activity.  Consciousness  is 
given  up  to  the  wonder  feeling,  the  trying  to  discriminate  be- 
tween the  harmful  or  healthful  properties  of  the  new  expe- 
rience. 

Savages  and  boors  are  mainly  interested  in  knowing  whether 
it  is  "good  to  eat,"  if  not  directly  injurious,  and  the  query  of 
the  "civilized"  man:  "  How  much  money  are  you  going  to 
make  out  of  it  ?  "  His  eternal  cui  bono  for  all  activity,  his 
failure  to  appreciate  any  mental  effort  which  will  not  fill  his  or 
his  neighbor's  intestine,  shows  how  little  evolution  has  done 
for  "civilized"  man  in  developing  his  diffusion  apparatus  aside 
from  gustatory  connections. 


CLEVENGER — Physiology  and  Psychology.  219 

Anxiety  is  anticipation  of  possible  harm,  and  is  only  possible 
in  animals  with  a  well  developed  nervous  system  with  its 
memory  registrations,  for  fear  cannot  be  anticipated  were  there 
no  memory  of  past  fear  or  pain.  The  tendency  to  depressed 
exhibitions  show  the  relationship;  as  there  is  no  immediate 
danger  to  elude  or  fight,  the  anger  fighting  attitudes  would 
avail  nothing,  diffusion  of  the  disagreeable  feeling  interferes 
with  cell-nutrition,  and  depression  occurs,  relieved  by  occa- 
sional starts,  when,  through  the  vividness  of  the  anticipation, 
the  worst  seems  to  have  been  realized.  Fitful,  troubled  sleep 
is  of  this  nature,  as  the  senses  cannot  at  this  time  correct  the 
feelings.  Throwing  off  anxiety  is  the  substitution  of  an  activ- 
ity which  will  so  interfere  with  the  impression  as  to  make  it  of 
little  effect. 

The  poorly  coordinated  emotions  of  the  infant  are  shown  in 
its  expressing  in  a  different  way  excitement  for  both  pleasure 
and  pain.  Its  pleasures  are  mainly,  at  first,  only  ingestive,  its 
pains  refer  to  excretory  impediments  and  to  want  of  food 
Wonder  is  every  moment  displayed,  for  its  cerebrum  mainly 
consists  of  a  diffusion  apparatus  with  imperfectly  developed 
higher  reflex  arrangements  anywhere  in  the  body.  Fear  next 
arises,  then  anger. 

Disgust  and  Satisfaction  are  well  shown  through  the  signs 
of  negation  and  assent,  the  shake  of  the  head  and  the  nod 
thereof,  which  Darwin  has  shown  to  be  universal  modes  of  ex- 
pression in  all  ages  and  among  all  peoples.  This  was  derived 
from  the  infantile  nod  toward  the  breast  of  its  mother,  and  its 
turning  its  head  away  from  it  when  not  hungry,  or  when  dis- 
gusted. 

Disdain  is  a  form  of  contempt  into  which  Pride  enters,  the 
latter  emanating  from  a  consciousness  of  superiority  based, 
however  differentiated,  upon  a  muscular  consciousness  of 


22O  CLEVENGER — Physiology  and  Psychology. 

ability  to  overcome.  However  fallacious  or  mistaken  such 
feeling  may  often  prove  to  be,  the  belief  that  one  is  superior  to 
another  is,  in  such,  derived  from  a  full  habit  and  development 
of  muscles,  or  at  least  the  supposition  that  such  things  are 
possessed,  even  though  the  feeling  may  outlive  the  warrant 
for  it.  In  the  threatening,  disdainful  strut  of  the  peacock,  and 
the  sidelong,  impudent  glance  of  the  bully,  with  his  swagger, 
this  feeling  of  pride  is  begun,  and  association  may  extend  the 
matter  to  purse  pride  and  pride  of  brains,  the  pride  of,  as  Tom 
Hood  calls  him,  "  the  self-elected  saint."  The  stalk  and  up- 
lifted head  and  poise  of  the  body  betoken  the  muscular  deri- 
vation of  this  feeling. 

///  temper  is  a  form  of  anger  or  "touchiness"  which,  if  un- 
duly exhibited,  shows  the  animal  to  have  been  himself,  or  that 
his  ancestors  have  been,  subjected  to  often  recurring  annoyances, 
whereby  it  became,  or  was  supposed  to  be,  an  advantage  to 
frequently  show  one's  teeth  with  slight  provocation.  Indul- 
gence in  this  instituted  it  as  a  reflex,  and  we  have  all  grades  of 
this  irritability,  from  constant  to  occasional  snappishness,  with 
variability  in  its  manifestations.  Ill  health  or  badly  nourished 
cell  groups  in  the  body  may  occasion  irascibility,  which  is 
merely  a  faint  anger  effort,  a  threat,  a  snarl,  and  exhibits  the 
association  of  inner  with  outer  sources  of  irritation. 

Where  one  is  pre-occupied  and  a  certain  region  of  the  brain 
is  surcharged  with  blood,  the  interruption  puts  to  work  another 
group  of  brain  cells,  and  through  their  comparatively  poor 
supply  of  nutrition  they  act  fitfully,  irritably.  Until  equilibrium 
is  established  by  diversion  or  becoming  interested  in  a  new 
line  of  thought,  irascibility  may  continue.  But  this  irascibility 
may  be  vented  upon  any  and  everything  if  something  un- 
pleasant has  happened,  due  to  the  domination  of  a  feeling  and 
its  mastery  of  the  organism,  just  as  fright  may  control  the 


CLEVENGER — Physiology  and  Psychology.  221 

motions,  to  shut  out  all   other  impressions,  as  when  a  panic 
occurs. 

Sulkiness  is  offended  amour  propre. 

Self-love  is  based  upon  muscular  pride  and  its  differentiations, 
and  has  a  deeper  derivation  in  the  life-conserving  desire  to 
avoid  pain  and  cultivate  the  pleasant.  Things  which  gratify, 
be  they  adulation  or  food,  whether  they  pander  to  the  ideas  or 
the  intestines,  when  denied  us  awaken  feelings  of  resentment, 
which  is  a  mixture  of  hatred  and  disgust.  Anger  may  be  thus 
provoked  unless  fear  usurps  its  place. 

Determination  is  muscular  effort  decided  upon,  and  even 
though  the  determination  may  be  a  mental  one  and  have  refer- 
ence to  an  act  to  be  performed  years  hence,  the  muscles  are 
made  rigid,  often  the  teeth  and  hands  are  clenched. 

Guiltiness  is,  in  lower  animals  and  man,  shame  or  the  fear 
of  consequences,  more  or  less  direct.  Detection  is  the  thing 
avoided  for  the  guilty  act,  and  when  not  avoided,  according  to 
the  estimation  of  the  punishment  to  follow  will  be  the  depth 
of  the  shame.  The  punishment  may  be  corporeal  or  the  loss  of 
regard  of  another.  In  either  event  it  was  desirable  to  escape 
such  suffering,  and  in  proportion  as  the  punishment  is  sought 
to  be  averted  by  appeal  to  arms  or  through  expressions  of 
helplessness,  either  methods  of  attempted  escape  are  useful,  and 
even  though  in  cases  when  unavailing,  are  resorted  to  through 
the  principle  of  serviceable  associated  habit. 

Surprise  is  the  same  as  astonishment.  The  useful  habit  of 
opened  eyes  passing  as  an  associated  habit  to  all  feelings  of 
surprise,  even  though  opening  the  eyes  widely  could  be  of  no 
use.  For  example,  when  you  hear  a  piece  of  surprising  news 
you  cannot  understand  it  any  better  by  lifting  your  eyebrows, 
but  in  savage  and  animal  days  the  serviceable  habit  was  formed 
when  enemies  were  approaching  and  prey  was  to  be  obtained. 


222  CLEVENGER — Physiology  and  Psychology. 

Then  shading  of  the  eyes  from  the  sun  and  their  dilatation  were 
of  use.  This  corrugation  of  the  brows  has  such  a  derivation 
in : 

Perplexity,  meditation,  reflection,  deep  thought,  and  in  all 
other  states  wherein  nervous  diffusion  apparatus  is  concerned, 
and  where,  as  yet,  no  definite  line  of  action  is  determined  upon. 
Usually  with  the  determination,  if  it  be  complete,  the  "  brow 
clears  up,"  the  corrugations  disappear  and  the  facial  muscular 
fixation  takes  its  place,  characteristic  of  the  succeeding  emotion. 

Attention  is  heightened  perception.  The  organism  in  breath- 
less attention  is  "  bending  every  nerve"  to  the  perception.  The 
reflexes  are  stayed  elsewhere  and  the  nutrient  reflex  allowed 
to  concentrate  the  oxygenating  and  nutrient  blood  upon  the 
points  concerned  in  the  perception.  At  first  this  may  be  vol- 
untary, but  as  the  other  parts  become  denuded  of  blood,  they 
become  less  efficient  as  interrupters  of  the  engaged  sense. 

Concentration,  abstraction,  even  to  "  absent-mindedness,"  is 
thus  possible.  In  even  the  feeblest  of  these  stages  an  automatic 
motion,  such  as  winding  up  your  watch,  may  be  made,  and 
the  next  instant  you  cannot  recall  whether  you  have  done  so 
or  not.  Complex,  as  well  as  simple  reflexes  or  automatic  acts 
are  provided  for  through  repetition,  and  where  the  tracts, 
through  this  repetition,  have  been  built  up  to  require  but  trifling 
effort  to  start  them,  the  mind  may  be  working  its  diffusion 
tracts  with  conscious  effort  and  simultaneously  instinctive 
motions,  or  those  which  require  but  little  reflection  to  perform 
may  be  accomplished.  Darwin  mentions  a  lady  who  played 
on  her  piano  while  absorbed  in  watching  her  canary  die,  and 
when  it  was  dead  she  burst  into  tears.  The  unconscious  piano 
playing  had  become  such  through  much  practice,  and  was 
comparatively  instinctively  performed.  The  tension  of  her 
feeling  prevented  her  from  realizing  that  she  was  playing.  It 


CLEVENGER — Physiology  arid  Psychology.  223 

is  a  relief  to  distressed  feeling,  as  before  remarked,  to  move, 
and  when  embarrassed,  drumming  with  the  fingers,  twirling 
something  in  the  hand,  afford  a  measure  of  relief.  The  rustic 
scratches  his  head,  Darwin  says, "  as  though  he  felt  an  uncom- 
fortable sensation  there,"  when  puzzled. 

The  hunger  feeling  differentiated  in  the  sexual  and  origin- 
ated that  desire.  Association  transferred  the  desire  to  the 
means  for  its  gratification.  In  many  low  animals  and  savages 
veiy  little  of  the  sentiment  which  we  call  Love  exists,  but 
many  developed  animals  not  in  our  phylum  have,  like  the 
Wanderoo  monkey,  which  has  but  one  mate  and  dies  of  grief 
over  her  loss,  evolved  many  of  the  feelings  which  the  best 
of  us  attach  to  the  sentiment.  Herbert  Spencer's  inimitable 
description  of  the  compound  nature  of  this  affection,  enumer- 
ates the  pleasure  feelings  exercised  by  it,  such  as  personal 
beauty,  admiration,  respect,  reverence,  approbativeness  in  hav- 
ing been  selected  from  one's  rivals,  the  pleasure  of  attracting 
the  attention  of  others  as  having  been  thus  favored,  the  knowl- 
edge of  possession,  etc.  But  where  Spencer  speaks  from  ob- 
servation of  the  truly  respectable  class,  who,  through  cultivation 
of  the  higher  feelings,  are  able  to  stand  unconvicted  of  allow- 
ing the  baser  feelings  to  sway  in  courtship,  the  vast  mass  of 
the  truly  lower  classes,  with  the  savages,  seldom  couple  with 
sexual  desire  any  other  emotion.  The  lowest  men  are  very 
much  like  the  lowest  animals  in  this  regard,  and  the  refinement 
of  sex  association  has  developed  in  the  highest  animals  as  well 
as  in  the  highest  men.  Mere  conventional  social  position  has 
nothing  to  do  with  this  development.  Brutal  dispositions  crop 
out  in  dukes,  kings,  the  "gentry,"  etc., and  savages,  sometimes 
barbarians,  frequently  conjoin  other  and  better  feelings  with 
their  amours. 

The  absorbing  nature  of  the  unevolved  and  evolved  passion 


224  CLEVENGER — Physiology  and  Psychology. 

has  been,  next  to  the  hunger  desire,  the  most  potent  influence 
in  the  affairs  of  the  animate  world,  and  in  all  properly  consti- 
tuted persons  its  domination  is  not  to  be  gainsaid,  for  in  most 
lives,  at  some  time  or  other,  if  not  frequently,  all  actions  and 
other  feelings  are  subordinated  to  it. 

It  is,  however,  found  that  in  some  men  and  in  many  women 
the  unawakened  passion  may  slumber  through  their  lives,  or 
but  feebly  disturb  the  individual. 

That  this  is  the  case,  can  be  affirmed  in  spite  of  the  testi- 
mony of  roues,  who,  through  their  cultivation  of  beastiality, 
come  to  see  only  their  own  feelings  in  others.  In  women  there 
is  a  good  reason  lor  it.  Through  ages  the  dread  of  the  conse- 
quences of  the  gratification  has  operated  as  a  deterrent  influ- 
ence. Inducements  to  chastity,  direct  and  indirect,  are  held 
out  to  them  on  all  sides,  and  as  their  sources  of  information 
grow  broader,  the  knowledge  of  the  disastrous  consequences 
of  illicit  love  impel  them,  except  when  peculiar  circumstances 
set  all  such  considerations  at  rest,  to  be  guarded.  This  expe- 
diency, acting  through  inheritance,  to  repress  all  exhibitions  of 
the  basic  feelings,  eventually  the  repression  becomes  intensi- 
fied, abnormally  so  in  some,  to  the  extent  of  almost  unsexing 
them. 

When  other  faculties  are  active,  the  function  is  repressed 
through  dominance  of  absorbing  occupation,  hard  work,  under 
feeding,  some  forms  of  sickness,  etc.  On  the  other  hand,  lux- 
urious idleness,  absence  of  higher  motives,  general  emotional 
indulgence  and  low  associates  degrade  what  is  a  legitimate 
source  of  happiness  into  its  derivative,  precisely  as  we  see  in 
the  insane  person  all  his  vague  feelings,  his  unrest  from  the 
relatively  overfed  tissues  of  the  body,  with  absence  of  brain- 
control,  tending  to  increase  of  lowest  desires.  The  bulimia, 
or  ravenous  appetite  of  the  insane,  is  the  evidence  of  the  with- 


CLEVENGER — Physiology  and  Psychology.  225 

drawal  of  the  higher  desires  and  the  inordinate  development 
of  the  fundamental. 

Again,  in  others,  the  effect  upon  the  actions  of  the  cellular 
sexual  activity  may  be  apparent  in  diseases,  as  some  forms  of 
hysteria,  while  the  sufferer  is  absolutely  guiltless  of  any  knowl- 
edge of  the  source  of  her  vague  desires,  unrest  and  emotional 
aberrations. 

Degrees  of  pleasurable  feeling  culminate  in  the  smile  which 
had  primarily  the  useful  function  of  enlarging  the  mouth  pre- 
paratory to  taking  in  a  good-sized  morsel.  Spencer  has  ana- 
lyzed the  joyous  feeling  in  his  "  Physiology  of  Laughter."  In- 
congruity is  at  the  root  of  ludicrousness,  but  the  latter  does 
not  alone  excite  laughter.  Pent-up  feeling  must  find  some 
vent. 

Wonder,  on  the  contrary,  may  prevent  laughter ;  the  former 
makes  the  muscles  tense  while  the  latter  relaxes  them.  "  There 
is  a  good  physiological  basis,"  says  Spencer,  "for  the  popular 
notion  that  mirth-creating  excitement  facilitates  digestion." 
The  visceral  shaking  up  he  notes,  points,  in  my  way  of  think- 
ing, directly  to  the  deglutitive  chuckle  origin  of  the  process. 
Trie  palate  tickle  is  the  root  of  the  physiological  function,  and 
whoever  has  not  seen  the  pleased  grunts  of  the  savage  as  he 
gobbles  and  chuckles  over  his  food,  may  see  something  of  the 
origin  of  the  laugh  in  the  pig  pen  while  the  hogs  are  feeding. 
Things  which  tickle  have  for  their  origin  the  gratified  wriggle 
of  the  cesophageal  and  enteric  cells ;  when  the  tickle  occurs  epi- 
dermically,  laughter  is  produced  as  the  only  outlet  toward 
visceral  motion  possible  to  such  moleculo-molar  motion,  which 
when  it  occurs  internally  finds  vent  in  the  original  cell  assim- 
ilative activity. 

The  savage  "Ugh ! "  or  grunt  of  assent,  testifies  to  both  the 
derivation  of  satisfaction  expression  and  to  the  relationship  of 

15 


226  CLEVENGER — Physiology  and  Psychology. 

stomach  pleasures  to  laughter,  for  until  modified  by  cultiva- 
tion of  restraints,  laughter  is  but  a  succession  of  such  grunts; 
the  scream  of  laughter  and  occasional  tears  of  merriment  are 
due  to  the  overflow  of  energy,  or  the  operation  of  Darwin's 
third  principle  of  diffusion. 

The  dog's  method  of  betokening  pleasure  by  licking  your 
hand  is  equivalent  to  telling  you  that  you  are  good  to  eat,  and 
it  is  his  substitute  for  a  smile.  His  fawning  and  cringing  is  an 
acknowledgment  of  your  superiority,  and  he  licks  his  chops, 
often  hypocritically,  in  lieu  of  smiling  at  you  or  asserting  your 
"sweetness."  Darwin  notes  that  some  negroes  more  directly 
express  this  appetite  association  by  rubbing  their  bellies  when 
pleased. 

Hobbe's  well  known  suggestion  of  glee  having  its  foundation 
in  a  self-superiority  feeling,  and  the  multitude  of  other  theories 
with  those  of  Spencer  and  Bain's,  indicate  that  a  variety  of 
mainly  pleasurable  states  provoke  mirth.  It  appears  very  clear 
to  me  that  as  the  eating  motions  are  the  lowest  exhibitions  of 
pleasure,  laughter  has  been  developed  thereupon,  and  the  multi- 
tude of  mental  and  bodily  conditions  inducing  this  expression  of 
pleasure  and  other  feelings  influence  the  expression  through  asso- 
sociation. 

Mobility  of  features  and  ability  to  express  the  feelings  vary 
greatly  in  different  persons,  and  it  is  not  always  safe  to  judge 
of  what  others  feel  by  their  expressions,  for  repression  is  de- 
veloped in  races  which  learn  the  inexpediency  of  exhibiting 
their  thoughts  outwardly  as  the  child  does.  The  detrimenal 
character  of  such  exhibitions  determines  the  deceit  of  the 
cloaked,  inhibited  expression,  and  even  the  substitution  of  the 
sickly,  insincere  "society  smile"  or  smirk. 

The  showing  of  emotion  by  others  strikes  us  as  "  greenness  " 
and  awkwardness.  Nevertheless,  contempt  for  this  is  mingled 


CLEVENGER — Physiology  and  Psychology.  227 

with  admiration  for  the  absence  of  deceit  in  the  perpetrator, 
an  admiration  founded  in  the  pleasure  we  experience  in  know- 
ing that  we  may  benefit  by  that  absence,  in  that  person. 

Outcries,  at  first  accidentally  induced  through  diffusion,  ex- 
citement of  respiratory  muscles,  were  found  to  answer  several 
purposes,  and,  as  Darwin  notes,  the  infant  has  developed  extra- 
ordinary ability  in  this  line  through  finding  how  promptly  it 
instigated  relief  through  others.  Many  forms  of  outcries,  such 
as  yells,  shrieks,  etc.,  are  still  diffusion  effects  through  inability 
to  make  more  serviceable  diversion  of  nerve  excitement.  The 
sexual  selection  development  of  singing  is  well  known  to  have 
influenced  bird  evolution,  and  in  troubadour  days,  and  occa- 
sionally in  our  own  times,  the  serenade  has  the  same  end  in 
view  as  the  Lieder  oline  Wortc  of  the  cats.  The  evolution  of 
language  has  been  a  simple  process  of  phonation  compound- 
ing. This  is  known  as  the  "bow-wow  theory,"  which  has  its 
proof  in  all  ethnological  and  philological  investigations. 
Recently  Mr.  Gushing  added  other  proofs  from  his  study  of 
the  Zuni  Indians. 

A  remarkable  cerebral  fact  may  be  cited  in  point.  A  large 
area  of  the  fronto-parietal  part  of  the  brain,  especially  on  the 
left  side,  is  now  known  by  cerebral  anatomists  as  the  "  sym- 
bolic field,"  for  the  reason  that  the  gesticulations  of  speech, 
writing  and  other  means  of  communication  are  grouped  there, 
and  destruction  of  these  areas  bring  about  a  loss  of  ability  to 
speak,  write,  or  otherwise  gesticulate,  all  the  way  from  paral- 
ysis of  the  members  to  mere  inability  to  recall  a  word  or  letter, 
though  the  ability  to  speak  or  write  the  word  or  letter  exists,  and 
can  be  temporarily  exercised  if  the  thing  forgotten  be  repeated 
in  spoken  or  written  words.  The  aphasia  may  be  for  writing, — 
agraphia ;  for  spoken  words, — aphasia,  together  or  separately. 

Hysterical  and  insane  persons,  and  young  children,  rudely 


228  CLEVENGER — Physiology  and  Psychology. 

vent  their  excitement  in  screams,  because  evolved  channels  for 
expression  are  denied  them. 

Blushing,  in  my  opinion,  was  originally  a  low  nutrient  reflex 
of  the  sympathetic  system.  Sudden  impressions  of  nearly 
every  kind  produced  a  suffusion  of  the  cephalic  parts,  which 
developed  divisions  of  this  general  reflex  and  enabled  the 
animals'  brains  to  have  blood  sent  to  particular  parts.  Blushing 
is  a  diffusion  effect  not  so  evident  in  hairy  or  thickly  cuticle d 
animals,  and  both  natural  and  sexual  selection  has  perpetuated 
it  through  its  representing  modesty,  a  form  of  timidity  or  fear. 
Such  visible  acknowledgment  of  superiority  accorded  the  male, 
mostly,  being  very  gratifying  to  the  self-conceit. 

In  man  such,  and  other,  diffusion  evidences  as  tremblings, 
are  reprobated  as  weaknesses  and  do  not  excite  the  admiration 
of  the  other  sex,  hence  their  repression  has  gone  on  in  the  male 
line  with  development  in  the  female.  Ontogenetic  modifica- 
tions have  taken  place  in  the  mixing  of  male  and  female  pecu- 
liarities. This  modifying  tendency  prevents  wide  differences 
in  the  sexes  in  other  things  aside  from  direct  sexual  matters. 

Sighing  was  originally,  as  it  now  is,  serviceable  as  an  inspi- 
ratory  act,  and  directly  affords  relief  from  the  oppression  of 
imperfect  oxygenation  of  the  pulmonary  blood.  From  other 
oppressed  feelings  clustering  around  this  sensation  through 
resembling  it,  the  sigh  of  relief  from  any  and  all  oppressed 
feelings  has  arisen  as  an  expression  for  all  of  them.  The  asso- 
ciation of  feelings  of  oppression  is  a  direct  one,  through  a 
slowed  respiration  being  set  up  by  depression  of  the  function, 
whatever  may  be  the  cause. 

Depression  has  reference,  then,  to  a  respiratory  interference. 
Dyspnoea  is  painful  and  the  sigh  is  an  effort  for  relief.  The 
"love-lorn,"  the  sympathetic,  etc.,  sighs  are  all  of  this  character. 

Weeping. — With  the  absence  from  the  water  which  had  bathed 


CLEVENGER — Physiology  and  Psychology.  229 

the  piscine  eye,  the  batrachian  readjusted  the  optic  capabilities 
by  acquiring  a  tolerance  for  living  on  land  and  having  occa- 
sional swims,  but  the  lachrymal  gland  was  formed  through  the 
posterior  cells  being  drawn  upon  by  the  corneal  and  sclerotic 
parts  until  development  made  the  fluid-furnishing  function 
easy.  The  saline  tears  are  of  the  nature  of  sea  water.  With 
this  pain  of  exposure  to  light  and  the  dessication  of  the  eye- 
ball, there  became  associated  the  endeavor  to  relieve  other 
forms  of  pain  by  the  process  of  weeping. 

The  shutting  of  the  eyes  during  screaming  is  shown  by 
Darwin  to  be  serviceable  in  overcoming  the  distension  of  the 
optic  by  the  blood  sent  there  in  the  act. 

Sneezing  and  Coughing,  Darwin  regards  as  originally  volun- 
tary expulsive  acts  of  fishes,  when  any  objectionable  material 
was  introduced  into  their  respiratory  or  pharyngeal  passages. 
From  this  arose  the  involuntary  reflex  acts  in  us  for  the  expul- 
sion of  any  irritating  matter  in  those  parts.  The  built  up 
reflexes  operate  alike  for  all  irritations  or  stimulations  of  an 
irregular  nature,  such  as  are  induced  by  odors,  congestions, 
accumulations  of  mucus,  etc.,  where  at  first  only  the  coarser 
materials  affected  those  areas.  This  is  only  one  of  the  myriad 
transferences  of  volitional  to  involuntary  or  instinctively  per- 
formed reflexes. 

The  expression  of  Helplessness,  as  the  cringe  of  man,  is,  like 
the  small  dog's  throwing  himself  on  his  back  before  the  large 
one,  a  serviceable  attitude,  and  appeals  to  sympathy.  Darwin's 
entire  principle  of  antithesis  I  pass  into  his  first  principle  of 
serviceable  associated  habit.  The  antithetical  emotional  expres- 
sion did  not  arise  as  antithesis  simply.  That  was  a  coincidence. 
But  the  antithetical  cringe  of  humility  was  originated  as  a 
serviceable  appeal  to  another,  the  serviceability  being  the  first 
consideration  and  the  antithesis  to  the  strut  of  pride  being  the 
means  of  performing  the  serviceable  act. 


230  CLEVENGER — Physiology  and  Psychology. 

Patience,  Resignation,  are  serviceable  as  appeals  to  sympathy 
and  directly  as  conserving  the  strength  for  the  things  we  can 
do  from  wasting  them  in  fruitless  emotional  display.  Help- 
lessness is  the  ultra  expression  of  both,  and  in  abject  cases 
passes  into  despair. 

Suspicious-ness  has  in  it  the  fear  of  harm  to  self,  and  the  fur- 
tive glance  by  which  it  is  characterized  comes  from  the  desire 
not  to  be  caught  watching,  but  nevertheless  a  wish  to  closely 
scrutinize.  The  diffusion  shunt  apparatus  of  the  cerebrum 
and  other  intervertebral  homologues  are  brought  into  use  in 
this  feeling.  When  it  rises  to  confirmation  of  the  doubts,  then 
the  suitable  reflexes  to  the  secondary  feeling  appear. 

Physiognomists,  such  as  Lavater,  strove  to  picture  Jealousy 
and  Maternal  Love,  but  Darwin  shows  that  there  are  no  such 
expressions.  Jealousy  may  not  impart  a  pleasant  look,  but  it 
may  produce  dozens  of  different  expressions,  from  suspicious- 
ness  to  rage.  The  artist,  by  his  judicious  accessories,  makes 
the  beholder  think  he  sees  maternal  love  in  the  mother's  face 
as  she  bends  over  her  infant,  but  wipe  out  the  cradle  and  its 
contents  from  the  picture,  and  substitute  a  poodle  or  something 
good  to  eat,  and  the  expression  will  fit  the  change  as  well. 
The  expression  of  love  between  the  sexes  is  a  masked  excita- 
bility ;  the  rapid  heart-beats,  when  they  meet,  the  blushes  and 
pleased  "  good  to  eat  "  smile,  are  all  this  best  of  sentiments 
afford  us  in  expression. 

Parental  Love  has  often,  by  Avriters,  been  ridiculously  as- 
sumed as  the  cause  of  the  species  perpetuation.  It  does  not 
take  a  very  astute  observer  long  to  see  that  the  getting  of 
children  holds  a  very  subordinate  part  in  sexual  desires;'  often 
it  is  very  undesirable.  The  daily  community  of  interest  and 
the  appeals  which  children  make  upon  our  sympathies,  their 
helplessness,  and  the  rule  which  causes  the  benefactor  to  like 


CLEVENGER — Physiology  and  Psychology.  23 1 

the  one  he  benefits  more  than  the  benefited  likes  the  benefactor, 
operate  to  create  parental  love. 

To  a  large  extent  the  mother's  love  is  a  selfish  one,  for  the 
infant  is  part  of  herself,  its  functions  are  so  dependent  upon 
her  own  as  to  make  this  love  natural.  Among  the  wealthy  who 
neglect  their  children,  and  among  the  very  poor  who  do  the 
same  through  inability  to  do  otherwise,  the  hearth-stone  affec- 
tion is  not  developed  as  in  the  middle  classes,  who,  after  all, 
are  the  anchor  classes  of  the  world. 

A  favor  received  becomes  a  source  of  irksome  sense  of  ob- 
ligation ;  one  imparted  awakens  a  feeling  of  satisfaction  in 
having  lain  another  under  tribute  of  regard.  In  children,  how- 
ever, who  take  everything  as  their  due,  or  whose  interests  are 
bound  up  with  their  parents,  the  mutual  love  is  more  likely  to 
be  enduring.  Ch.  Ribot,  and  others,  show  that  family  affection 
between  children  and  parents  is  not  due  to  any  inherent  mys- 
tery, such  as  novel  writers  fasten  upon  it,  by  citing  cases  where 
bastard  offspring  may  be  tenderly  loved  by  the  father  whose 
confidence  has  been  betrayed,  and  that  adopted  children  often 
arouse  true  parental  love. 

Sympathy,  as  Spencer  shows,  arises  as  an  altruistic  feeling 
through  our  conceiving  ourselves  in  the  place  of  the  one  need- 
ing the  sympathy.  We  must  have  first  felt  the  sensation  in 
ourselves  which  arouses  our  sympathy  for  it  in  another.  It 
is  owing  to  this  that  ladies  may  crush  bugs  and  flies,  and  the 
naturalist,  who  studies  them  under  the  microscope  and  realizes 
their  kinship  in  pain  and  pleasure  to  ourselves,  usually  refrains 
from  unnecessary  infliction  of  pain.  A  vivisectionist  for  this 
reason  is  more  likely  to  be  merciful  than  the  "  beastiarian  " 
who  decries  him.  The  rich,  for  this  reason,  seldom  feel  for  the 
poor.  In  fact,  he  who  rides  in  a  carriage  has  an  involuntary 
contempt  for  him  who  goes  afoot.  The  knowledge  that  this 


232  CLEVENGER — Physiology  and  Psychology. 

feeling  is  natural  should  only  operate  toward  overcoming  it. 
Unpleasant  information  of  this  kind  usually  invokes  a  storm 
of  denial  from  the  mob,  they  prefer  to  think  themselves  de- 
scendants of  the  angels,  and  refuse  to  analyze  their  own  senti- 
ments. The  unwelcome  truths  should  be  faced  and  an  honest 
endeavor  be  made  to  develop  good  traits  we  do  not  possess. 

The  artistic  and  scientific  tendencies  evolved  slowly  from  the 
barbarian  love  of  display,  originating  in  the  decorative  tendency 
of  animals,  still  remaining  to  a  certain  extent  among  human 
females  in  their  regard  for  finery  and  jewelry.  Desire  for 
adulation  is  at  the  root  of  all  progress  in  the  arts  and  sciences. 
It  is  a  blow  to  the  scientist  to  see  his  work  appropriated  with- 
out credit,  and  an  amusing  toadyism  is  apparent  in  semi-sci- 
entific circles,  appropriately  mentionable  here,  mixed  with  the 
filching  tendency  alluded  to. 

A  Chicago  writer  dislikes  to  credit  any  one  in  Arkansas  with 
a  good  thought.  A  New  York  or  Boston  man  cannot  con- 
ceive of  Chicago  originating  anything,  and  across  the  sea  the 
general  run  of  scientists  avoid  any  mention  of  America  or  its 
workers,  if  possible.  Darwin  was  a  notable  exception  to  this 
rule,  for  he  was  above  such  paltriness.  Quotations  from  the 
American  Naturalist  and  other  United  States  journals  abound 
in  his  writings.  Then  the  occidental  toady  will  foster  this 
spirit  by  quoting  only  'from  the  East  and  ignoring  everything 
American. 

The  average  Eastward  plagiarist  has  not  been  above  stealing 
ideas  from  his  disdained  confreres,  and  I  mention  this  with  all 
the  more  feeling  because  I  have  seen  my  own  work  thus  ap- 
propriated until  I  have  come  to  the  pass  of  noting  such  things 
with  a  view  to  their  publication  in  the  near  future. 

Huxley  calls  attention  to  the  truly  snobbish  nature  of  the 
house  dog,  who  will  bark  at  an  illy-dressed  beggar,  but  treats 
the  well-dressed  stranger  with  cordiality  or  indifference. 


CLEVENGER — Physiology  and  Psychology.  233 

These  reprehensible  acts  arise  from  the  mistaken  notions 
of  what  constitutes  expediency.  The  apeing,  toadying,  snob- 
bery, etc.,  are  founded  in  a  desire  to  attract  attention,  as  one  way 
of  ministering  to  self-conceit  Plagiarism  is  stupid  theft,  and 
in  all  an  advantage  is  supposed  to  have  been  gained  by  the 
animal. 

The  views  of  some  of  the  metaphysicians  may  be  appropri- 
ately quoted  with  reference  to  the  feelings  or  emotions  herein 
considered  :  James  Mill  says  that  "  when  an  agreeable  sensa- 
tion is  conceived  of  as  future,  but  without  one's  being  certain 
of  it,  this  state  of  consciousness  is  called  hope  ;  if  one  is  cer- 
tain of  it,  it  is  called  joy.  When  a  disagreeable  sensation  is 
conceived  of  as  future,  but  uncertain,  that  state  of  conscious- 
ness is  called  fear ;  if  it  is  certain,  it  is  called  sorrow.  An 
agreeable  sensation,  or  the  idea  of  that  sensation  joined  to  the 
cause  which  produces  it,  engenders  affection,  or  love  for  that 
cause.  A  disagreeable  sensation  joined  to  the  idea  of  its  cause 
engenders  antipathy,  or  hatred  for  that  cause." 

According  to  Spinoza,  "  Love  is  nothing  but  joy  accom- 
panied by  the  idea  of  an  exterior  cause.  Hate  is  nothing  but 
sadness  accompanied  by  the  idea  of  an  exterior  cause." 


234  CLEVENGER — Physiology  and  Psychology. 


CHAPTER    XIV. 
DERIVED  ACTIVITIES,  MAINLY  MENTAL. 

Hesitation  and  doubt  are  either,  or  both,  lower  "automatic" 
or  mental  conditions  developed  in  proportion  as  we  pass  from 
the  lower  forms  of  cell  life  to  the  best  coordinated  organization. 
In  the  lowest  form,  hesitancy  and  doubt  are  due  to  attractive 
and  repulsive  influences,  so  balanced  as  to  have  not  reached  a 
resultant  which  will  determine  a  motion.  Indeterminate  diffuse 
motions  exhibit  the  greatest  degree  of  this,  and  as  the  effect 
becomes  more  definite,  then  hesitation  or  doubt  passes  to  an- 
other state.  Doubt  is  an  action  of  the  diffusion  apparatus,  or 
the  inability  to  gauge  past  or  present  impressions  to  action. 
Hesitancy  is  a  form  of  doubt  and  is  given  rise  to  through  its 
presence.  As  Belief  may  pass  to  the  extent  of  elaborating  an 
instinctively  acting  reflex  system  so  that  it  may  occasion 
"unconscious"  movements,  Doubt  is  related  to  Meditation, 
Thought,  Reason,  in  having  no  such  thoroughly  built  up  ap- 
paratus. 

Volition. — The  end  of  deliberation,  thought,  hesitation,  or 
doubt.  It  is  the  coordinated  volitions  of  the  cells,  the  resultant 
of  their  activities,  and  merges  into  the  purely  reflex  at  one  end 
of  the  scale  to  the  relatively  free  will  of  the  individual  with 
the  best  brain  organization.  Free  will  is  relatively  such  only. 
You  cannot  do  what  your  organization  debars  you  from  doing 
and  the  component  cells  act  through  natural  influences.  If 
the  adjustment  and  associated  activities  of  the  cells  be  such  as 
to  enable  the  wisest  ( most  expedient )  action  in  behalf  of  the 
organism  or  its  aims,  then  we  have  that  degree  of  free  will 


CLEVEXGER — Physiology  and  Psychology.  235 

development  which  distinguishes  the  best  intentioned  ( hence 
wisest)  man  from  the  criminal  or  lunatic,  whose  erratic,  illy-bal- 
lanced  volition  shows  him  to  be  controlled  by  an  imperfectly 
arranged  association  system  of  means  to  ends.  In  this  sense 
the  wise  man  is  comparatively  free,  and  the  criminal  and  luna- 
tic are  in  subjection  to  a  badly  arranged  nervous  system  which 
does  not  unite  the  cells  in  their  best  interests. 

The  question  of  responsibility  enters  here,  and  is  seen  to  be 
a  purely  relative  matter,  incapable  of  definition  or  fixation. 
The  jurists  have  all  sorts  of  artificial  standards  of  responsi- 
bility and  are  unable  to  determine,  except  approximately,  and 
then  only  occasionally,  the  degree  of  responsibility  of  the  indi- 
vidual for  acts  committed.  In  the  knowledge  that  criminality 
is  lunacy,  in  that  it  leads  the  man  to  do  things  incompatible 
with  his  immediate  or  remote  interests  (and  the  interests  of 
society  are  his  own),  the  expediency  doctrine  shows  us  why 
free-booters  in  one  age  are  sane,  and  in  another  criminals,  and 
in  still  another  insane.  The  irresponsibility  or  responsibility 
of  those  who  decide  upon  that  of  others,  is  thus  determined  as 
a  matter  of  no  moment.  They  are  guided  by  extrinsic  circum- 
stances; and  the  result  between  judge,  jury  and  popular  opin- 
ion is  a  juggle  any  way.  All  such  relative  actors  and  activities 
being  in  an  irresponsible  flux,  and  accident  determining  the 
"decision"  in  the  end,  which  is  a  pure  result  of  caprice,  always. 

The  remotest  influence  may  "decide"  whether  the  arraigned 
shall  hang  or  be  given  a  fortune.  The  loss  of  a  note,  the  state 
of  digestion  of  the  judge  or  juror,  etc.  And  the  clearest 
cases,  apparently  warranting  a  favorable  decision,  often  merit  a 
reversed  treatment  to  that  obtained.  Spencer  gives  the  best 
account  of  volition  not  being  absolute. 

Reason  and  Thought,  to  some  extent  synonymous,  involve 
hesitation  and  doubt,  where  thought  is  not  used  in  the  sense 
of  reverie. 


236  CLEVENGER — Physiology  and  Psychology. 

Logic,  or,  as  it  has  been  called,  the  "art  of  reasoning,"  may 
in  all  its  sub-divisions  be  included  in  Deduction.  Impressions 
are  accepted  as  facts,  and  resemblances  and  differences  sought, 
whatever  the  sub-divisions  of  the  deductive  process  may  be. 

The  only  test  of  truth  we  possess  is  the  one  mentioned  by 
Edgar  A.  Poe,  Consistency. 

Instinct  depends  upon  definition  of  tracts  in  the  nervous 
system,  and  hence  succeeds  reason,  though  inherited  or  other 
instinct  may  be  disintegrated  through  tearing  down  of  tracts 
by  reason  and  subsequently  reinstated  as  instinct  again  of  a 
different  kind. 

Reverie,  may  be  conceded  to  be  an  indulgence  in  mem- 
ories with  but  little  of  a  definite  end  in  view.  Reasoning  im- 
plies a  doubt,  and  preceding  determination  is  a  species  of 
hesitation  as  palpable  as  that  which  precedes  the  choice  of  a 
reflex  from  the  spinal  cord  and  is  of  the  same  nature.  In  the 
latter  case,  the  diffusion  fibrillae  of  the  cord,  or  the  neuroglia, 
or  both,  are  acting  indeterminately.  In  the  case  of  reasoning 
and  in  Meditation  the  brows  are  often  contracted,  as  though  to 
shade  the  eyes,  and  respiration  slowed  as  in  attention,  the 
feeling  is  allied  to  pain  and  associated  with  anticipation  and 
the  desire  to  concentrate  the  perceptions,  often  apparent  in 
occasional  elevation  of  the  eye-brows  and  other  attention  atti- 
tudes. The  diffusion  fibers  of  the  brain  are  allowed  full  sway, 
and  according  to  the  revivability  of  past  experiences  in  terms 
of  memory  sensations  the  result  of  the  deliberation  will  be 
evident.  Through  incessant  reaction  to  certain  stimuli  a  spinal 
cord  reflex  may  be  inevitable.  This  depends  upon  a  definite 
arrangement  of  the  reflex  adjustments  to  the  stimulus  and  con- 
stitutes instinct.  If  the  stimulus  be  novel  and  adjustment  be 
not  fully  made  to  it,  and  more  than  one  mode  of  automatism 
be  possible,  then  the  hesitation  in  the  choice  of  reflexes  is 


CLEVENGER — Physiology  and  Psychology.  237 

the  reasoning  of  the  cord.  If  no  provision  for  action  is  prac- 
ticable, then  diffusion  is  the  only  result  and  the  tremblings  and 
other  general  diffusion  manifestations  occur.  Similarly  with 
the  brain  workings.  If  a  certain  line  of  action  is  the  invariable 
result  of  a  certain  precedent  impression,  then  the  higher  in- 
stinctive motions  or  reflexes,  whether  simple  or  complex  mat- 
ters not,  result.  If  two  or  more  acts  or  modes  of  expression 
are  possible  as  a  result  of  the  deliberation,  then  the  cerebral 
diffusion  apparatus  will  "  choose  "  one  or  the  other  exhibition, 
the  choice  being  a  predetermined  resultant  of  a  set  of  condi- 
tions the  most  likely  to  be  associated  under  existing  circum- 
stances of  blood  supply,  brain  structure  and  previous  modify- 
ing influences. 

If  no  provision  for  determination  is  possible,  then  the  diffu- 
sion apparatus  finds  no  outlet  in  activity  for  its  stimulation 
and  diffusion.  Effects  similar  to  those  furnished  by  the  cord 
follow,  and  owing  to  the  greater  blood  consumption  and  the 
preponderance  of  brain  tissue  over  spinal  cord  tissue,  so  will 
the  results  of  painful  indecision  be  proportionably  greater  than 
those  attending  the  lower  centers.  In  extreme  cases,  exhaus- 
tion, mental  anguish,  psychic  pain,  which  is  generally  the  same 
as  bodily  pain  and  relieved  by  the  same  medicaments,  or 
frenzy,  may  be  the  result 

Wonder  is  expressed  by  the  facial  contortions  of  attentive 
perception.  In  proportion  as  the  wonder  is  greatest,  the  diffu- 
sion apparatus  in  the  vicinity  of  the  cerebral  gyri  involved  in 
the  perception  are  suffused  with  blood  through  the  nutrient 
reflex  action.  As  soon  as  memory  or  recollection  drops  the 
thing  wondered  at  to  'a  cognized  or  familiar  matter,  wonder 
ceases,  and  a  resultant  motion  of  the  body  is  made,  or  the  for- 
mer activities  are  resumed.  In  this,  and  in  perception,  accord- 
ing to  their  depth,  the  nutrient  reflex  assists  the  associating 
methods,  which,  when  effected,  other  actions  succeed. 


238  CLEVENGER — Physiology  and  Psychology. 

Wonderment  has  been,  and  is,  powerful  in  constructing  the 
diffusion  fibrils  of  the  brain,  which  in  turn  cohere  in  fasciculi 
to  form  the  radiating  tracts,  and  in  the  human  infant  and 
simian  the  wonder  faculty  distinguishes  them  as  reflecting  ani- 
mals, which  revolve  in  their  minds  the  possibilities  of  what  they 
perceive  being  convertible  to  their  own  uses.  The  infant  who 
thrusts  everything  into  its  mouth,  shows  what  its  ideas  of  util- 
ity are,  and  the  chimpanzee  is  divided,  in  his  inspection  of  the 
novel  thing  between  doubts  as  to  its  injuriousness  or  edibility, 
as  is  the  infant  later  in  life. 

In  fact,  the  majority  of  men,  whether  "civilized"  or  savage, 
lose  all  interest  in  matters  which  do  not  refer  to  a  pretty  low 
sense  gratification,  and  it  is  only  by  development  of  the  reason- 
ing (cerebral  fibrae  arcuatae)  abilities  that  attention  can  be  sus- 
tained over  things  which  involve  higher  considerations — such, 
for  instance,  as  abstract  good  to  a  people,  instead  of  concrete 
good  to  one's  self. 

The  Imagination  is  an  exercise  of  memory,  the  superimposi- 
tion  of  recollections,  the  recalling  of  images  of  things  and 
acts,  and  the  vividness  of  these  images  depend  upon  the  exer- 
cise of  the  faculty  and  the  reasoning  powers  owned  by  the  in- 
dividual. It  is  but  a  form  of  thought,  and  is  definite  or 
indefinite  in  what  it  yields,  according  to  the  cerebral  structure 
of  the  person.  It  has  Reverie  at  one  extreme  of  its  indul- 
gence and  profound  abstraction  at  the  other. 

Ideas  are  resultants  of  thought  operations.  A  fixed  idea  or 
conviction  is  a  belief  or  conception  of  an  actuality  judged  as 
such  by  the  person's  action  conforming  thereto.  James  Mill 
recognized  ideas  as  mental  reproductions  of  sensations. 

The  desire  for  Liberty  or  Freedom  is  not  an  exalted  feeling, 
for  it  is  identical  with  the  locomotory  desire  of  the  amoeba,  which 
we  said  was  associated  inextricably  with  hunger  in  that  animal 


CLEVENGER — Physiology  and  Psychology.  239 

and  separated  from  it  only  when  locomotory  apparatus  was 
differentiated.  It,  however,  has  been  evolved  from  the  concrete 
selfish  to  the  abstract  altruistic  love  of  national  freedom. 

The  ^Esthetic  feelings  Spencer  has  shown  to  be  dependent 
upon  the  "play  desire  "  of  lower  animals.  The  wish  to  expend 
"  nervous  "  energy  in  rythmic  or  other  motions.  Dancing  and 
the  pleasure  derived  from  music  belong  to  this  feeling,  the  uni- 
versality of  rythm  in  nature,  and  particularly  in  our  own  mo- 
tions and  sensations  inspire  the  love  of  music  and  timed 
motions,  the  drama,  etc. 

Belief,  Confidence,  Trust,  Assurance,  Conviction,  concededly 
relate  to  action.  "  Preparedness  to  act  upon  what  we  affirm  is 
admitted  on  all  hands  to  be  the  sole,  the  genuine,  the  unmis- 
takable criterion  of  belief."*  It  is  based  upon  an  assumed 
knowledge,  which  in  turn  depends  upon  memory.  Bain  also 
says,  "  it  never  occurs  to  the  child  to  question  any  statement 
made  to  it  until  some  positive  force  on  the  side  of  scepticism 
has  been  developed." 

Prescience  depends  upon  memory,  and  is  corroborated  in 
precise  proportion  as  the  knowledge  of  past  facts  or  impres- 
sions justify  the  prediction  of  their  recurrences  and  the  acute- 
ness  of  the  individual  in  seeing  and  foreseeing  relationships. 

Forethought  falls  in  this  faculty  of  prescience. 

My  treatment  of  the  sensory  and  molar  activities  in  this 
essay  is  open  to  the  charge  of  a  want  of  profounder  classifica- 
tion. I  have  purposely  withheld  the  usual  divisions  of  these 
phenomena,  principally  because  such  separations  of  unconscious 
and  conscious  acts,  feelings,  desires,  emotions,  and  mental 
states,  are  purely  artificial ;  and  next,  because  it  would 
require  too  much  space  to  treat  such  matters  fairly.  In  pref- 
erence to  presenting  abstract  groupings  which  would  have 

*Bain,  op.  cit,  p.  505. 


240  CLEVENGER — Physiology  and  Psychology. 

included  all  the  activities  in  a  general  way,  the  plan  adopted 
seemed  more  conducive  to  a  clearer  understanding.  A  descrip- 
tion of  the  evolution  of  a  few  of  the  states  in  the  order  of  their 
development  has  been  attempted,  and  I  have  been  forced  to 
reserve  further  consideration  of  matters  relating  to  the  special 
psychology  of  man  for  a  bulkier  volume,  to  follow  the  publica- 
tion of  this. 


CLEVENGER — Physiology  and  Psychology.  24 1 


CHAPTER    XV. 

THE  LAW  OF  EXPEDIENCY  AND  OPTIMISTIC  CONCLUSION. 

Bain  *  gravely  mentions  Benjamin  Franklin's  "  Moral  Alge- 
bra, or  method  of  deciding  matters  for  one's  self,"  by  setting 
down  all  the  pros  and  cons  and  striking  a  balance,  the  prepon- 
derance of  the  remainder  deciding  the  step  to  be  taken.  Pru- 
dential algebra  is  another  name  for  the  process. 

With  the  operation  of  the  law  of  expediency  under  our 
eyes  every  minute,  and  its  active  shaping  of  all  animate  affairs, 
neither  Bain  nor  his  predecessors  have  been  able  to  see  its 
application  in  Franklin's  method,  nor  in  the  multitude  of  simi- 
lar processes  resorted  to  unconsciously,  but  naturally,  every 
day  by  every  animal. 

What  is  expedient  to  do  must  be  determined  by  every  ani- 
mal, according  to  his  circumstances  and  his  way  of  thinking. 
His  ideas  of  what  may  be  desirable  will  guide  him  usually, 
and  whether  one  desires  food,  another  its  representative,  money, 
or  another  a  perpetual  continuance  of  possession  of  both  in 
immortality,  the  expediency  gauge  of  the  individual  may  be 
applied  by  considering  what  he  deems  desirable  and  the  prac- 
ticability of  obtaining  it.  Considerations  of  the  proper  meth- 
ods for  the  accomplishment  of  an  end  also  involve  questions 
of  feasibility  and  expediency.  For  it  would  not  do  to  destroy 
an  end  in  the  method  of  its  attaining.  Yet,  through  bad  logic 
or  the  want  of  mastery  of  the  emotions  or  desires,  frequently 
this  is  done. 


The  Emotions  and  The  Will,  p.  413. 
16 


242  CLEVENGER — Physiology  and  Psychology. 

The  advantages  arising  from  a  continuance  in  "  doing  right" 
become  so  apparent  as  to  make  that  action  often  habitual, 
whereupon  the  animal  takes  great  credit  for  his  conscientious- 
ness. 

A  friend  of  mine,  whose  learning  and  the  value  of  whose 
opinions  are  known  the  world  over,  was  formerly  beset  by 
lawyers  and  judges  in  expert  cases.  They  considered  it  expe- 
dient to  annoy  him  by  scurrility,  as  it  amused  the  court  room 
mob  and  reacted  against  him  with  the  average  juryman.  Fi- 
nally, the  judges  and  the  attorneys  were  reminded  that  while 
they  temporarily  raised  a  laugh,  such  a  thing  as  printer's  ink 
existed.  The  ability  of  my  friend  to  defend  himself  against  a 
recurrence  of  such  insults,  acted  as  a  deterrent  upon  their  ex- 
uberance, and  finally  induced  them  to  consider  common  de- 
cency expedient.  Every  animal  has  had  to  learn  the  lesson, 
and  the  highest  are  willing  to  profit  by  the  experience  of  others, 
and  not  undergo  the  usual  preliminary  discomfitures. 

Conscience  has  arisen  from  this  law  of  expediency,  and  no 
matter  whether  the  thing  to  be  dreaded  as  a  consequence  of 
the  act  has  a  real  existence  or  not,  so  long  as  there  are  un- 
pleasant consequences,  or  the  animal  imagines  there  are,  flow- 
ing from  certain  acts,  the  disagreeable  association  of  the  acts 
with  their  real  or  imagined  outcome  constitute  that  feeling 
of  depression  or  anticipation  of  evil  accompanying  the  individ- 
ual standard  of  bad  action.  The  pleasure  derivable  from  a 
good  act  is  similarly  associated  with  a  reward,  such  as  all 
ecclesiasts  have  found  it  expedient  to  hold  out  to  all  men  as  a 
consequence  of  a  certain  line  of  action.  By  inheritance,  the 
habit  of  decency  may  become  second  nature  to  a  person,  and 
the  advantages  are  so  evident  to  him  that  unless  circum- 
stances conspire  to  destroy  the  feeling,  he  prefers  to  "  do 
right,"  because  it  is  easier  to  do  so. 


CLEVENGER — Physiology  and  Psychology.  243 

The  penny  given  to  the  beggar  whom  you  may  never  see 
again,  awakens  your  self-approbation.  It  is  your  reward. 
If  you  have  inherited  benevolence  you  feel  "  guilty  "  if,  when 
the  opportunity  arises,  you  omit  doing  a  kind  act.  Your  desire 
to  escape  the  disagreeable  consequences  of  having  throttled 
your  kindly  promptings  may  retrace  your  steps  and  cause  you 
to  make  a  sacrifice  as  a  "  sop  to  Cerberus." 

Most  charitable  acts  are  perfunctorily  performed,  and  the 
public  conscience  is  assuaged  through  its  alms  by  proxy.  The 
tax-payer,  from  whom  the  stint  has  been  wrenched  by  law, 
usually  refers  the  alms  seeker  to  the  commissioners  for  the 
poor,  and  satisfies  his  "  conscience  "  in  a  way  which  could  not 
be  done  were  the  public  to  be  depended  on  to  do  its  own  alms- 
giving. 

Only  a  few  animals  and  men  have  correct  conceptions  of 
the  highest  expediency.  The  majority  act  up  to  the  crudest, 
shallowest  ideas.  Thus,  anger  exhibition  and  stupid  selfishness 
characterize  their  dealings,  where  the  few  control  themselves 
and  have  exalted  aims  in  life. 

Many  who  see  what  is  expedient  are  not  able  to  govern 
their  passions  and  are  placed  at  the  same  disadvantage  as  those 
who  are  blind  to  their  best  interests. 

The  history  of  the  animated  world  consists  of  the  individual 
and  collective  triumph  of  higher  over  lower  expediency.  It 
may  be  seen  in  the  wiles  and  doublings  of  the  chase ;  the  sur- 
vival of  the  fittest  in  multitudes  of  instances ;  the  gradual 
elevation  of  the  standard  of  fitness  as  expediency  adopts  a 
higher  plane ;  selfish  individual  savage  scrambles  and  brawls 
are  superceded  by  tribal  and  national  defensive  and  offensive 
coherence  against  enemies ;  the  interweaving  of  interests  all 
over  the  world  through  the  extension  of  commerce  and  rapid 
communication  put  an  end  to  international  quarrels,  and  with 


244  CLEVENGER — Physiology  and  Psychology. 

the  growth  of  wisdom  (expediency  recognition)  happiness  is 
increased  and  will  eventually  reach  a  plane  which,  though 
relative  and  incomplete,  will  be  incomparably  greater  for  all 
than  can  now  be  conceived. 

Herbert  Spencer's  early  writings  were  pervaded  by  attacks 
against  the  expediency  philosophy,  but  later  he  tacitly  adopted 
it.  His  original  idea  was  the  omnipotency  of  a  "  moral  law," 
and  he  made  a  sincere  attempt  to  expound  the  Christian  ideal 
of  such  a  law.  Many  of  his  notes  on  this  topic  are  touching 
and  beautiful.  For  instance,  he  points  to  the  fact  that  the  moral 
law  assigns  no  punishment  for  its  infringement ;  it  directs  us 
to  what  should  be  done  by  way  of  elevating  mankind,  but  is 
silent  concerning  penalties.  This  seems  very  like  a  recogni- 
tion of  universal  irresponsibility,  and  is  quite  reconcilable 
with  both  adjurations  to  forgiveness  and  the  chemical  affinity 
theory  of  life  which  pervades  this  book. 

If  a  cell  or  organ  may,  under  certain  favorable  circumstances, 
be  developed  into  any  other  kind  of  cell  or  organ,  and  -as  we 
positively  know  to  be  the  case,  circumstances  largely  control  the 
character  of  men,  it  is  folly  indeed  to  be  otherwise  than  forgiv- 
ing, seeing  that  we  are  none  of  us  responsible  in  any  particular. 
But  that  this  cannot  at  present  be  adopted  generally  comes 
from  the  unevolved  condition  of  human  nature  and  society.  A 
flexible  arbitrary  standard  of  responsibility  will  exist  as  long 
as  true  expediency  does  not  govern  all.  Penalties  and  rewards 
are  accompaniments  of  all  Nature's  laws.  Pains  will  be  min- 
imized and  the  pleasures  increased  as  fast  as  natural  laws  are 
recognized  and  allowed  to  govern  action,  until  finally  the  high- 
est adjustment  at  present  conceivable  will  evolve  a  prevailing 
gentleness,  honesty,  justice,  forgiveness,  and  an  altruism  which 
will  prove  to  be  an  exalted  egoism  because  the  best  interests  to 
all  will  be  subserved  through  its  governance. 


CLEVENGER — Physiology  and  Psychology.  245 

I  claim  that  Expediency  is  the  Moral  Law.  Several  hundred 
years  ago  "stand  and  deliver"  was  a  legitimatized  salutation,  and 
the  booty  obtained  no  more  afflicted  the  average  conscience 
than  the  looting  of  a  public  treasury  to-day  would  interfere 
with  the  ordinary  politician's  digestion.  Mercantile  interests 
gradually  extended  protection  and  the  free-booter  gave  way  to 
trade  knaveries,  such  as  adulterations,  embezzlements,  etc.  A 
good  old  German  novel, " Soil  und Haben"  idealizes  commercial 
integrity  in  the  character  of  a  merchant  who  kept  an  account 
with  God  into  which  he  passed  all  his  debits  and  credits,  and 
who  tried  to  make  his  dealings  consistent  with  the  supposition 
that  the  deity  would  punish  all  unfairness  with  his  fellow  men. 

Such  characters  will  prevail  numerically  and  in  their  suc- 
cesses, eventually,  as  a  higher  ideal  of  expediency  is  created. 
Spencer  shows  that  when  money-getting  ceases  to  be  the  chief 
interest  of  life,  and  nobler  aims  are  substituted,  the  world  will 
look  back  with  horror  at  the  conceptions  of  happiness  in  this 
age,  and  "honesty  in  tatters"  will  be  regarded  as  a  martyr 
among  the  "successful"  thieves  of  this  generation,  while  in 
generations  to  come  honesty  will  not  be  allowed  to  be  the 
unfittest  to  survive.  Natural  penalties  will  swiftly  follow  the 
derelictions  of  low-grade  expediency  worshippers  and  the  re- 
wards will  be  more  justly  distributed. 

Teach  children  to  be  upright  because  it  is  wisest  so  to  be, 
and  show  them  how  it  befalls  that  respect,  position  and  honor 
accrue  from  ordinary  decency,  and  such  instruction  is  likely 
to  have  more  weight  than  all  the  usual  indefinite  promises 
and  appeals  to  their  fears  that  can  be  made. 

The  saying  that  "  every  man  has  his  price  "  means  more 
than  its  vulgar  interpretation.  If  you  seek  broad  and  worthy 
fields  of  life  and  can  accustom  yourself  to  derive  happiness 
from  noble  work  ( I  will  not  attempt  to  define  what  this  may 


246  CLEVENGER — Physiology  and  Psychology. 

be,  for  though  ideals  may  differ,  a  generally  fair  understanding 
of  what  nobleness  is,  exists ) ;  if  retrograding  to  a  state  of  par- 
asitism or  developing  an  overweening  taste  for  wealth,  which 
is  founded  upon  the  gustatory  and  has  its  associations  there- 
with so  closely  that  an  unscrupulous  capitalist  is  merely  a 
hypertrophied  intestine ;  if  becoming  cruel  and  selfish  are  re- 
pugnant to  your  ideals  of  being  happy,  then  your  better  long- 
ings, in  proportion  to  their  intensity  and  the  consistency  with 
which  you  endeavor  to  satisfy  them,  places  you  beyond  the 
bartering  of  your  higher  expediency  pleasures  for  that  which 
the  social  sharks,  foxes  and  tape-worms  scramble. 

Nevertheless,  the  robber  and  one  who  works  for  "eternal 
rewards  "  differ  only  in  degree  of  expediency  ideals. 

The  reason  why  good  eventually  triumphs  is  simply  because 
development  of  intellect  renders  people  capable  of  seeing  what 
is  truly  expedient,  that  same  faculty  is  associated  with  the 
ability  to  thwart  the  low  grade  intellects  of  those  whose  expe- 
diency conceptions  are  lower.  Besides,  in  innumerable  ways, 
evil  tends  to  destroy  itself,  even  though  it  may  require  thou- 
sands of  years  and  involve  the  destruction  of  many  unfit  to 
exist  nations. 

"  But,"  the  affrighted  mind  cries  out,  "what  consolation  is 
all  this  to  me  as  an  individual  ?  The  world  may  in  its  endless 
cycles  be  growing  better,  and  my  childrens'  children  may,  in 
living  up  to  the  true  expediency,  realize  happiness,  but  what  is 
that  to  me  ?  I  want  some  assurance  of  the  future  !" 

This  is  the  natural  lower  feeling,  the  genuinely  selfish  atomic 
affinity  for  the  most  neighboring  kindred  atoms.  The  contem- 
plation of  death  is  pleasant  to  no  one.  It  may  be,  even  seems 
likely,  that,  with  the  evolution  of  the  conceptions  of  true  hap- 
piness and  the  better  acquaintanceship  with  the  inflexibility  of 
Nature's  laws,  more  resignation  to  them  will  be  acquired,  even 
to  the  extent  Bulwer  describes  in  his  "  Coming  Race." 


CLEVENGER — Physiology  and  Psychology.  247 

The  question  has  been  asked:  "Does  the  amoeba  ever  die?" 
When  we  regard  the  countless  multiplications  of  the  initial 
form  and  consider  that  the  offspring  are  parts  of  the  parent, 
the  living  in  one's  children  is  the  only  kind  of  immortality  we 
can  observe.  More  than  this  it  is  folly  to  affirm  in  the  pres- 
ent state  of  knowledge ;  yet,  as  Huxley  says,  the  audacity  of 
those  who  claim  to  know  all  about  the  hereafter  is  only  equaled 
by  the  arrogance  of  those  who  deny  its  existence.  Agnosti- 
cism, which  is  the  wise  refraining  from  questions  which  we  can- 
not settle,  is  our  only  refuge. 

We  may  take  comfort  in  the  feeling  that,  as  that  which  is 
universally  good  succeeds  inevitably  over  that  which  is  bad, 
the  operation  of  such  a  law  will  not  in  the  end  overlook  the 
individual.  Only  let  us  strive  to  deserve  a  higher  kind  of  hap- 
piness. 


INDEX. 


PAGE. 

Absent-mindedness,  .....        228 

Abstraction,        .  .  173,  222,  232 

Abstract  processes,   .  .  55 

Actinism,  ......  138 

Adaptation  (see  Adjustment). 

Adjustment,  .  38,  56,  64,  67,  78 

Esthetic  feelings,  .  .  239 

Affection,  .  .  .        233 

Agamogenesis,  .  .  47 

Agraphia,  ....         227 

Albumen,  .....  5 

Allantois,  ...  57 

Altruism,  .  .  .37,  68,  81,  106,  244 

Amnesia,  ......         175 

Amnion,  .  .  .  .  .  5$ 

Amoeba,      .  .        7,  9,  13,  16,  19,  20,  31,  35,  48,  62 

Amoeboid  Corpuscle,  .  .  .  .  10,  52 

Amphioxus,  .        31,  68, 71,  72 

Anaesthesia,        ......  108 

Anaesthetics,  .  ....         166 

Anencephalism,  .  .  .  159, 

Anger,         .  .  .         217 

Annelida,  .  ....  30 

Antipathy,  .  .  .  .  233 

Anxiety,  ...  .  219 

Aphasia,  .  174, 227 

Apncea,  ...  77 

Arrested  Development  (see  Teratology). 

Arteries,  ...  42 

Arterial  motions,  .  .  .  .17,  33,  76,  82 

Ascidia,  .  .  ...  29,  34 

Assimilation,  6,  17,  18  34,  37,  49,  53,  87 

Associated  Serviceable  habit,  ....  153 

Association  (see  Law  of). 

Astonishment,  ......         218 

Astrodiscus  arenaceus,     .....  27 

Assurance,  ....  239 


INDEX. 


Asymbolia, 
Atavism, 
Attention, 
Audition, 


PAGE. 

174 

22,  15,  50,  52 

222 

87,  136,  141,  178 


Bees, 

Belief, 

Bile, 

Blood, 

Blood  globule, 

Blushing, 

Brain, 

Brain  evolution, 

Brain  functions, 

Breeding  (see  Genesis). 


51 

234,  239 
37 

25,  33,  35,  65,  75,  77,  83,  154,  163 

.      30,  34,  82 

228 

77,  88 

180 

178 


Carbon-dioxide, 

Cartilage, 

Castration, 

Catalysis, 

Cerebrum, 

Cerebellum, 

Cerebro-spinal  nerves. 

Change  of  plane, 

Chemism, 

Chemical  affinity, 

Chladni  sand  figures, 

Chorionic  villi, 

Cholesterin, 

Cilia, 

Circulation  (see  Blood) 

Cloaca, 

Ccelom, 

Cognitions, 

Cold  blooded  animals, 

Color, 

Color  blindness, 

Commissures, 

Composition  of  forces, 

Concentration, 

•Confidence, 

Consciousness, 

Conscience, 

Consistency, 

Contempt, 


10,  12,  17,  31,  33,  77,  82,  162 

29 

14 

7 

98 

146 

74 

125, 144 
108, 138 

.      2,  37,  51,  62,  67,  72 

.  73,  168 

57 

162 

23 

59 

.      30,  31,  33 

.      2,22 

9 

139 
139 

.      71,  76,  83,  176 

64 

222 

239 

4,  7,  17,  22,  106,  202 
242 
230 
217 


INDEX.  Ill 

PAGE. 

Contractions,  .                 .                 .                .                 .31,  35,  60,  67 

Conviction,         .  .                                                  239 

Convulsions  (see  Tetanus). 

Coordinations,  ...                                                  .67 

Cortex  of  Brain,  ...                                                  176 

Coughing,  .                                                                                .        229 

Cranium,             .  .45 

Criminality,  .                                                                                    •         235 

Cyanogen,           .  .                .                                                  162 

Oeep  thought,          .                .  .222 

Dejection,           .  .                .                                 212 

Deliberation,               .  .170 

Delivery,             .  .                                                      45 
Desires,       .                                ...      11,  14,  18,  21,  72,  85,  94 

Desire  for  freedom,           .                 .  239 

Desire  for  salt,            ...  38 

Despair,               ....  212 

Desiccation,                .                .  .8 

Determination,               *    .  ...                 221 

Development,            .  47,  57,  64,  72 

Differentiation,                   .                 .  64,  67,  72,  75 

Diffusion,                    .                .  127,  142,  147,  176 

Dilemma,                             .  .                 .        136,  179 

Disadvantages  of  the  upright  position,  .                 .           38 

Disdain,                .                 .  ...                219 

Disgust,      ...  .                                 .214 

Disease,                .                 .                .  .                 .                 .                  87 

Doubt,         .                                 .                 .  .                 ,                .234 

Dreams,  ......        172,  207 

Dyspnoea,                    .  .                                  153,  228 

Eating  (see  Ingestion). 

Effort,  ....  .143 

Egoism,       .....  37,  08,  86,  106,  244 

Electricity,  ....    10,62,108,142,163 

Embryology,  .....  51,  71,  84 

Embryos,  .  .  .  .  .  9,  52,  56 

Emotions,  .  2,  78 

Encapsulation,    ......  28 

Enterocoele,  ...  30 

Enteron  (see  Intestine). 

Ergot,  ....  .36 

Ethology,    .......          37 

Excitement,        .  .  .  .  .  206 


IV  INDEX. 

PACK. 

Excretion,.  ....  17,27,33,37,82,80 

Exhaustion,        ....  65 

Expectant  attention,                  .                                                  .  l1*^ 

Expediency,        .....  61,24!) 

Eyes,           .  W 

Faculties,                           .  12 

Faintness,                    .  •         179 

Fatty  degeneration,           ...  32,  68 

Fear,           .                .                .  212,233 

Feelings,             .  2,  22 

Femoral  changes,     ...  45 

Fins,    .  .60 

Fissures,     .                                                                   •  .183 

Food,                   .                .  11,37,63,68,74 

Forces,         ...  .    11,  16 
Forethought,       . 

Fright,         ...  .147 

Gamogenesis,    . 

Ganglia,     .                                                                                 •  67,78,89 

Gastrsea,               .                                 .  *7 

Gastrula,                                                      .~  24 

Generosity  (see  Altruism). 

Genesis,  "...  -        20, 47, 84,  85 

Germ  cells,         .  20,  48 

Gratitude, 

Gravitation,        .                                 .  •    1°»  12,  108 

Gray  matter  (see  Neuroglia) 

Grief, 88,212 

Growth,               .                .                •  13,19,47,48,56 

Goitre,         . 

Guiltiness, 

Habit,         ....                                •  150,  155 

Hemoglobin,      .  30,  33,  36,  65,  82 

Haemorrhoids, 

Happiness,  ... 

Hatred,        .  217,  233 

Hearing  (see  Audition). 

Heart,                    ...                                 -  31,35,77,82 

Heat,  .  .  .  •  6.  10,  61,  109,  142,  163 

Helplessness, 

Hemianresthesia, 

Hermaphrodism,                 .                                                    .  .                   51 


INDEX.  V 

PAGE 

Hernia,       .  43 

Hesitation,          .  .  .        170,  324 

Heterogenesis,  ...  47 

Hibernation,        .  ....  9,  207 

Hippocampi,  .  .  .         198 

Homogenesis,    ....  47 

Hunger,      ....  13,18,64,72,76,79,85 

Hope,  ...  233 

Hydro-dynamics,       .  .  .  .  .  .46 

Hydrogen,  ......  36 

Hysteria,    .....  15 

Ideas,          ...  22, 238 

Idiots,  ......  184 

111  temper,  .  ....         220 

Imagination,       .  ....  238 

Immortality,  .  .  .  .  .  .247 

Ingestion,  .  .  .  .  .  .29,74 

Inheritance,  .  ...  53, 79,  169 

Inhibition,  .  .  .78, 79,  81,  99,  148,  179,  195 

Injury,         .  ...  77 

Insanity,  .  .  .  .  .      1, 46,  235 

Instinct,      .  ...       (>7,  79,  96,  150,  169,  236 

Intervertebral  Ganglia,  ....         180,  183 

Intestine,  .     24,  30,  31,  33,  35,  37,  64,  72,  77,  82 

Irritation  (see  Stimuli). 

Involution  of  Organs,       ...  .59 

Impact,       .  .  .  .60 

Impulse,  ......  149 

Impregnation,  .  .  .  .14 

Inogene,  .  .  .  163 

Jealousy,  .  ...         230 

Joy,      .  .  ....        212,233 

Kangaroo,  .  .  .  .  .  .60 

JL,achrymal  gland,  .  .  .  .  .  75,  88 

Language,  ......         227 

Laughter,  .......  225 

Law  of  Association,  .  14,  65,  73,  76,  87,  105,  176 

Law  of  Least  resistances,  .  .  .    63, 73,  144 

Law  of  Ohm,  .  .  .  .  .  .143 

Law  of  Relativity,  .....        126,  139 

Law  of  Valved  veins,  .  .  .  .  .41 


VI  INDEX. 

PAGE 
Learning,  .  ...  176 

Leech,        .......  89 

Lemurida?,  .  .  .44 

Light,  .  .       6,  10,  108,  137 

Limb  development,  .....  59 

Liver,  .  .  .  .36,  74,  162 

Locomotion,       .  .  .  11,  16,  21,  27,  29,  33,  63,  64,  79 

Logic,         .  ....        236 

Love,  .  .  .        223,  233 

Lung  (see  Respiration). 

Lymphatics,  .  33 

Magnetism,        ......  36 

Malthusian  doctrine,  .  ,  .  .  .46 

Mammary  glands,  .  ...  84 

Mania,         .......         175 

Marsipobranchii,  ...  68,  71 

Marsupialia,  .  .  .  44,  84 

Maternal  love,  .....  230 

Meditation,  .  .  .        222,  234,  236 

Megatherium,    ......  44 

Memory,     .  2,  18,  24,  87,  171,  203 

Menstruation,     ......  81 

Menstruation,  vicarious,  .  .  .  .85 

Mental  correction,  .....  103 

Mental  perversion,  .  .  .  .15 

Metagenesis,       ....  47 

Metamorphosis,          ....  .47 

Microscopy,         .  .  .  .  .  -5,  54,  73 

Milk,  ...  84 

Mind,  .  .  .  .  2,  52,  55,  95,  170 

Modesty,     .  .  .  .  .    "  .228 

Molar  motion,  .....  75 

Molecular  motions,  8,  17,  19,  67,  72,  75,  82,  110 

Monism,  .  .  .  .  39,  60 

Monotremes,  .  .  .  .  .     59,  84 

Monstrosity  (see  Teratology). 

Moral  law,          ....  .244 

Morbid  appetites,      .  .  .  .  .  .15 

Morula,  .  ....      23;,49,  52 

Mosquito,    .  .  .  .  .  .  .         136 

Motility,  .  ..  .  7,  22,  31,34,  62,  73',  77,  82,  90,  147 

Motor  fibres  and  cells,  .....         146 

Motor  memory,  ...  97,  174 

Motor  nerves,  ....  .  74, 89,  121 


INDEX. 


Vll 


Muscles, 
Myelitis,      . 

Natural  selection, 
Neoplasms, 
Nerve  beginnings. 
Nerve  cells, 
Nerve  currents, 
Nerve  definitions. 
Nerve  endings, 
Nerve  force, 
Nerve  plexuses, 
Neural  crest, 
Neuroglia, 
Neurotics, 
Nitrogen, 
Nutrient  reflex, 
Nutrition, 


PAGE. 

25,  31,  34,  59,  63,  65,  67,  74,  76,  77,  90,  146,  162 

45 

81,  37,  51,  56,  72,  109 
33 

25,  27,  61,  63,  69,  74,  115 
157 

....          65,  144 

29,66,69 

90 

159 

28,  61,  69,  75 
70 

67,  70,  74,  80,  90,  120,  159 
165 
162 

75,  153,  177 
9,  33,  76 


Odor  (see  Olfaction). 

Olfaction,   . 

Ontogenesis, 

Organic  matter, 

Osmosis, 

Osteal  cells, 

Otoliths, 

Outcries, 

Ovaries, 

Oviparous  genesis, 

Ovoviviparous  genesis, 

Ovum, 

Oxygen, 


14,  72,  74,  87,  98,  141 

53,  56,  68,  69,  87 

5,  8,  12,  34 

33 

29 

137 

227 

8* 

.  *47,  84 
47 

9,51,54,83 
10,  12,  17,  30,  63,  65,  77,  81,  122,  153 


Pain, 

Pangenesis, 

Pantheism, 

Parasthesias, 

Paralysis,    . 

Parental  love, 

Parthenogenesis, 

Patience, 

Pelvis, 

Perception, 

Perennibranchise, 

Peristalsis, 


18,  84,  87,  206 

52 

60 

142 

22 

230 

48 

230 

43 

139,  178,  222 

.  31,  34 

82 


Vlll  INDEX. 

PACE 

Perplexity,  .  .  .  .  .222 

Pessimism,          .....  60 

Pharyngobranchii  (see  Amphioxus). 

Phosphorus,  ....  162 

Phrenology,        .  .  134 

Phylogenesis,  ....  53,  56,  69,  88 

Physical  forces,  .  .  .  7 

Planeseda,  ....  23 

Planula,  .  .  .  50,  54 

Pleasure,    .  .  jg,  206 

Plethora,  .  7  21,  B3,  54,  64 

Pneumogastric  nerves,  ...  71,  74,  153 

Poisons,  ....  166 

Polar  forces,  .  .  .59 

Potential  embryonal  state,  ....  54 

Potential  energy,       .  ...         145 

Prehension,        .  .  7,  11,  IS,  16,  17,  21 

Prescience,  .  ...         239 

Pressure,  .  .  .  .  .  .  21 

Pride,         .      .  .  .  .  .  219 

Primum  mobile,  .  .  .  .  60 

Prolapsus  uteri,         ...  .  .  43 

Protoplasm,  .  .  .          5,11,17,25,34,55,62,79 

Protozoon,  .  .  6,  13,  16 

Pseud-haemal  system,        .  ...  30 

Pseudonematon  nervosum,  .  ,  25,  61,  115 

Pseudo-parthenogenesis.  ....  47 

Puberty,  .  «  .  14 

Pulsation,  .  .  .31,  76,  82 

Purkinje  cells,  ......         146 

Reason,  .  .  170,  234,  236 

Reflection,  ...  .  222 

Reflex  action,  ....  76,  78,  148 

Relativity  of  Sex,      .....  48,  50,  52 

Repletion  (see  Plethora). 

Reproduction,     .  13,  17,  19,  48,  56 

Reproduction  of  lost  members,  .  .  .54 

Resignation,        .  .  .  230 

Respiration,  ,  12,  17,  31,  74,  82 

Responsibility,    .  .  .  .  235 

Reverie,  .  ...         236 

Rhizopoda,  .  ...  28 

Rhodopsin,  .  ...  68,  138 

Rudimentary  organs,        ...  .  58,  70 

Rythm,        .  .  .  .  .  81,  34, 78,  81,  107 


INDEX. 


IX 


Sacrum, 

Saliva, 

Sanity, 

Satiety  (see  Plethora). 

Satisfaction, 

Scolecida, 

Secretion, 

Segmentation. 

Selfishness  (see  Egoism). 

Self  love,    . 

Senility, 

Sensation, 

Sensory  fibers  and  cells, 

Sensory  nerves, 

Sensory  organs,  , 

Sex, 

Sexual  desire, 

Sexual  organs, 

Sexual  perversion, 

Sighing,      . 

Sight, 

Size  and  function,     . 

Sleep, 

Smell  (sec  Ol faction). 

Smile, 

Sneezing, 

Society, 

Sorrow, 

Sound, 

Species  origination, 

Sperm  cell, 

Sphincter  muscles, 

Spinal  cord, 

Spinal  nerves,     . 

Spirits,  low  and  high, 

Splanchnic  nerves, 

Spontaneous  generation, 

Stimuli, 

Stigmatization, 

Stomach, 

Sulci  of  Brain, 

Symbolic  field  in  the  brain, 

Sympathetic  Nervous  System, 

Sympathy. 

Syn  amoeba, 

Survival, 


PAGE. 

44 
75 
63 

219 
24 

27,  37,  75 
56,86 

221 

175 

2,  21   73,  78,  79,  90,  107,  147,  202 

146 

89 

.      67,  73,  89 

20,  48,  52 

.      13,  19,  85 

.    52,59 

15 

228 

14,  68,  87,  137,  141,  177 

145 

94,  207,  219 

225 
229 

.    61,  86 
233 

109,  136 
51 

19,  48,  54 
35 

08,  70,  91,  97,  176,  180 

70,  89,  180 

212 

76,  83 

8 

.     '  35,  62,  79,  90,  146,  148,  209 

179 

83 

183 

201,227 

71,  75,  83,  85,  146,  151 
231 

19,  23,  48,  50,  52 
.       8,  42,  79 


X  INDEX. 

PAGE, 

Sulkiness,   .                                                .  .221 

Suspiciousness,                                    .                 .  .                                 230 

Swimming,                  ...  ...         148 

Tactile  sense,     .  .      21,  24,  83,  136,  141 

Tail,             ....  88 

Taste,                    .                                                  .  141 

Teleology,                   .  -1,  39, 42,  60 

Teratology,         ...  49 

Terror,     "  .                                                  .  .                         216 

Tetanus,               .                                                  .  77,147 

Thought,     .  !•">,  163,  23& 

Thymus,              ...  32 

Thyroid,      ...  32 

Timidity,             .  228 

Tinnitus  aurium,        .  •         142 

Tonsils,                ...  32 
Touch  (see  Tactile  sense  i. 

Trophic  nerves,          ...  •         151 

Trust,  289 
Tunicata,    . 

Urea,    .                                 ....  162 

Uterus,        .  •    43,84 

Vacuoles,                                                            .  16,  35,  82 
Vagus  (see  Pneumogastric). 

Valves  in  the  veins,  .                                            40 

Vaso  motor  nerves,            ...  151 
Veins,          ....    36,40 

Vermicular  motion,           .                 .                 .  33,  74 

Vertebrae,    .                 .  44 
Vibrations  (see  Molecular  Motions), 
Visual  purple  (see  Rhodopsin). 

Vitality,               .  -        8,12,62 

Viviparous  genesis,                    .                  .  ,                                   .    47,  84 

Volition,  1,  7,  200,  234 

Walking,  148 

Wallerian  degeneration,  161 

Weakness,                    .  .147 

Weeping,  228 
White  blood  corpuscle  (see  Amoeboid  corpuscle). 
Will  (see  Volition). 

Wisdom,     ...  .244 

Wonder,  .....  104,  225,  237 
Worms,       .......           89 


FOURTEEN  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 


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Renewed  books  are  subject  to  immediate  recall. 

MAR  2  5  1958 
Mr27'58JM 

2  Q  iq5E 
UL20'58JG 

291965 


LD  21-100m-2,'55 
(B139s22)476 


General  Library 

University  of  California 

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